73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: BlueCollarRon on February 21, 2009, 06:28:11 pm
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So here is my dilemma. I had a 350/350 in my '82 swb GM and I busted my crankshaft. That old block is complete garbage. So now I have a early 80's 350, or a 400 that is sitting in a 79' Chev in the yard. I plan to compete my truck in the mud drags, so faster times the better. On the other hand, I will be tearing it up with friends on the weekends. Lots of those trails are very long so....
In your opinion which would be the best option from our choices above?
I found this interesting read from another forum
http://www.greatlakes4x4.com/showthread.php?t=120939
http://www.youtube.com/watch?v=jkfGuDhB8_c
Utube: 350 races a 400
Thanks
Ron
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theres no replacement for displacement!
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I'd get a 400 personally, bigger is better in the same size package, but if you broke a crank, whichever engine you get you need a forged crank and rods instead of the stock cast crank. everybody hates 400 because they have heard this or that about cooling. most people who have had them love them. As long as you have steamholes in the right spot in the heads, no other equivelent small block can touch a 400. nowadays with everybody going to 383's. IMO 350's are the new 305, and 383's are the new 350. I'd reuse a 350 for the same reason one might reuse a 305. you already have it, or for a tad better fuel mileage.
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Get a stump puller!!
I didn't see an option to vote on a 383 stroker ;D
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Why would he build a stroked 350 when he already has a 400? The 400 is a nice small block and it's too bad they stopped making them. A few things to keep in mind with the 400 is build it for what it's meant to be and have a good cooling system. You will need to either get a set of drilled heads or drill a set of heads for the steam holes. I had two 400's and both of them were awesome. Keep the compression ratio streetable and use a dual plane intake manifold and don't go too crazy with the cam.
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My friend had a mean 79 k5 with a 400 with mild mods(not exactly sure other than intake and headers) that i was going to put through the mud bog at our county fair. It was a fast sucker. i worked hard getting that thing ready, fix tires, fixed the hubs, replace belts, ect. he had it for sale sign on it after i got it signed in there and sold it an hour before i was going to race. :'( It did great and place pretty high.
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My friend had a mean 79 k5 with a 400 with mild mods(not exactly sure other than intake and headers) that i was going to put through the mud bog at our county fair. It was a fast sucker. i worked hard getting that thing ready, fix tires, fixed the hubs, replace belts, ect. he had it for sale sign on it after i got it signed in there and sold it an hour before i was going to race. :'( It did great and place pretty high.
That would piss me off >:(
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the 400 gets my vote too...Vile has some good advice about the steam holes. I posted a link in another thread on here about a 400 sb with airflow research heads that made 490 hp and 529 ft-lb. Sounded like a good build, and if your budget doesn't allow they built the same engine with vortec heads and 1.5 ratio rockers (they used 1.6 ratio with the afr heads). Other than that everything was the same including the cam...that version made 427hp and 515 ft-lb or something like that.
Might be worth mentioning that the combo with the afr heads could run 87 octane iirc and they had to run 93 in the vortec headed one.
either way I think it could be done on a budget and you could upgrade to the afr heads down the road. that much torque would make anything go like a $#*(). They did all this with a stock 400 crank, evidently they're pretty strong.
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You would probably do better with a 327 turning high rpms. Mud bogging is all about rpms of the tires and floatation. Look for high rpm hp and don't worry about torque too much just make sure you have enough to get it up to speed. 327 uses the 350 bore and a 3.25 stroke crank as opposed to the 350's 3.48 stroke. Plus with the internal balance higher rpms are going to come a lot easier than destroking an externally balanced 400.
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Do the 400 with a 5.7 rod lenght. 383 don't breath as well as a 400 due the smaller bore that shrouds the valves. A 350 just has to work harder to get the job done and if you already have the 400 SBC then it is a no brainer. Forget the highwinding 327 if you drive this thing and do mudbogging on weekends, all that will happen with a 327 that you have to daily driver is a temperamental engine that wears out faster due to the low gearing. Highwinding equals big cam which means higher compression that leads to no street driving because big compression will not run on pump gas. I have a 406 that was built in the late 1980's for a magazine article (Strong Arm 406) in a Monte Carlo that runs high 12's on pump gas,drives on the street like a dream, and it does just like a late model car (starts without a hassle in the cold, runs with a shorter gear and pulls down 17 mph with a TH400)
Another consideration if you are willing to get another engine.........Oval port 396/402 BB with a hyd roller Cam, easy to build big torque, cheap to build cause it is out of not so saught after pieces.
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Go as big as you can afford for bogging. You can build a 400 to spin just like anything else ( buddy built one that would spin to 8000rpms), 327 would just have to work harder for the same amount of power. No brainer.. 400.
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Why would he build a stroked 350 when he already has a 400?
I'm gonna steal a line from my 4-yr old boy....."Because!".
I dunno, never had a 400, but, I have a 383 and that puppy has loads of torque. Torque is what makes an engine go. 'tis why they are called stump pullers. Love mine. Anyone else would love there's.
But, as mentioned, c.i.d. is boss. Go with displacement--i'm outvoted www.delbridge.net/install
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Look guys, stating your opinion as fact is just plain, well uneducated.
Fact #1 the 327 had the highest hp output of any naturally aspirated production gm sb engine until the 2002 Corvette z06
Fact #2 the 2002 z06 engine was a 350
Fact #3 the 08 Vette engine is 366ci
Fact #4 the 400 was only manufactured for 10 years, if it was so good why only make it for 10 years? They still made big blocks so the mpg thing is out the window.
Fact #5 the 400 was never used in the Corvette by gm which being the flagship Chevy car always got the best motors, yet the 327 was and so was the 350 as well as big blocks odd isn't it how the 350 and 327 are the 2 most popular corvette engines. I find it also interesting how during the 70's while the 400 was being produced the 350 was the base corvette motor.
Anyone ever wonder why most 400's output was around 250 hp which is around 100 hp less than the 327's? Ever wonder why gm did away with the 400?
A 400 turning 8000 rpms? On a daily driver? On a budget the OP could afford? That's a pretty big claim.
Why didn't GM bring back the 400 in the second generation small block? There has to be a reason especially with the Mustang walking all over everything Chevy made in those years.
Capt - I beg to differ with you. Getting a 327 to turn 8000 reliably is going to cost a lot less than a 400. A 327 makes 350 hp with a hyd cam, they actually call it the 350 horse 327 cam. You could drop a hyd roller cam in and get 400 hp. I think that should be all the power it would need and it can live in the 6000 rpm range all day long and be perfectly streetable, actually tame. Simple physics proves the shorter stroke of the 327 will spin faster than the longer stroke of the 400 or even the 350. The crankshaft even with no pistons attached will be capable of spinning faster. Have you ever watched a figure skater do there spin move? Did you happen to notice as they brought their arms and knees in towards the center they speed up? When their arms are out can be thought of as the longer stroke than when everything is close to the center line.
I agree that a big block is a better choice if it can be afforded because then the jump in horsepower allows you to use gearing to get those tires spinning at the right rpms. As an added benefit the bbc would still be very streetable.
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The 400 died because of emissions and no more huge cars. they were for torque in those big cars with better mileage than a 454. I agree the 375/327's were bad little engines, but a bear to drive on the street and a pita to maintain with the solid lifters. but either way, if the 327 was so great, where is it now? Also you said the if the 400 was so great how come they only made ot for 10 years, so why were 327's only made for 8 years. Ask lots of dirt track racers if they use 327s or 400's (rules allowing) they turn 5000+rpms. By the time the 327's went out, everything else was being choked by emissions junk, so of course they cant perform like that. The reason big inches is better is that you don't have to hop it up as much to make the same power, giving better reliability and driveability. if they had went all out and set up a 400 like they did that 375hp 327, we'd all be talking about that super impressive 400 chevy used to make. IF you set it up correctly, ANY chevy small block will turn 7000rpms all day. i see what you're saying about the physics, smaller stroke, less mass to move a shorter distance. the stroke difference between a 327 and a 350 is about the same as the difference between a 350 and 400. how many 327's turn 8000+ rpm's like 350's (with longer less capable strokes) in NASCAR and do it for 500 miles straight? 327 was just a stepping stone, like every other engine chevy has made or will make. Cubes make the difference, as an extreme example would you race a chevy small block 265 or a big block 572 for pink slips.
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Cool, great thread and info.
I'm definitely going with the 400, and I will build it up as much as my cash allows. Down the road I would like to bore it out, but for now I am going to swap motors and swap the carb from my 350 to the 400. That will get me back on the road for a while, at least until I get more cash. I still have another month until I can even think about spring.
So correct me if I am wrong, but I need heads with holes drilled in them to let out steam!? Is that a major problem with the 400sb for those without drilled heads?
I have read that due to the motor being externally balanced it can cause problems. What should I be worried about?
For the cooling system, as long as I have a fan for the radiator what more could I do? Would a fan even be beneficial?
Even though I made my mind up, keep the debate going, I'm learning a lot! :o
(http://i296.photobucket.com/albums/mm177/bluecollarron/CDP_Roller_406_S.jpg)
Small Block 400
(http://i296.photobucket.com/albums/mm177/bluecollarron/polished_alt_ps.jpg)
Small Block 350
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Nice looking engines^^^
Here's some info on the steam holes, where they are located, how to drill them. this guys putting 350 heads on a 400, but it applies to any head on a 400. The cylinder bores in a 400 are siamesed, or have no space between them like all other small blocks for coolant to flow between them. the steam holes let out air that can get trapped because of the siamesed bores. thats all it's for, they don't vent steam or anything like that.
http://www.gregsengine.com/350to400.htm (http://www.gregsengine.com/350to400.htm)
i think 400's got a bad rep from the start because all (or some) of the 400s from 1970 (first year) came with no steam holes in head or block, which made them overheat.
Main thing to watch for being externally balanced is that you must have a 400 specific flexplate/flywheel and harmonic balancer. Sometimes the outer shell of the balancer can slip and get out of phase with the inner hub, making the balancing be off.
as far as fans, you can't have too many, especially flogging on it in a mud bog or trail at slower speeds.
reason I'd recommend a forged crank at least is, while a cast crank (iron or steel) is plenty strong, when mudding, you may come up on more shearing-type (I hope that's the right word) forces. meaning if you are going all out and something all of a sudden puts a sharp strain on the engine, like if you full throttle went from gravel to asphalt it can put a hella lot of force on everything. since you broke a crank before, it may be a worthwhile upgrade so another block doesn't get destroyed.
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Thanks great advice. I definitely want a stronger crank, it still bugs me why it happened.
Just to clarify, those aren't my motors. Just nice eye candy
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Rev's mean diddly when it comes to power and torque when you are comparing powerplants. Useful torque and horsepower is what's important. If you want different operating driveline RPMS change your ratios. For a heavy truck with large tires larger displacement and a longer stroke will be better.
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..That 350 blinded me with its bling :o
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My buddies 400 was built for less than $2000 and it was balanced to spin to 8500, it saw it on several occasions, we street raced it during the winter.
Fact#1 = that was the official documented power of the motor. The 302 which was smaller in size made was documented at 290 at 4400rpms. It would spin to 8500... There was alot of discussion on this. NRE built one a few year back and it made 500hp@8500... BTW, all of GM's top motors were under rated. If you notice none of them were ever rated over 375 (this was for insurance reasons) BBCs were never over 435hp. BTW the L89 was rate 5 more HP than the Aluminum ZL1 which made realistic 500+hp also, same goes the L88 "race" motor, rated 430 hp @ 5200 rpm, it was good for 500+ at 6800
Fact #2 and 3 Not sure of the relativity... unless you saying GM also agrees bigger is better by going up in size, they did testing and speced the motor for durabiltity and performance when designing it... Same thing with the LS9 which is 378ci. Redline BTW is 6600...
Fact #4 10 years for the 400 is 3 more than the 327.. If you notice the trend, engines have gotten larger not smaller for performace reasons.
Fact #5 By the time the 400 came on the scene the Gas Crunch had begun and performance was thrown in the trash. No real development was done on anything up until about 1985 when the TPI came out.. BTW as far as numbers of engine with X motors the 350 buy FAR and the 283 were the more popular engines..
I think I have a pretty good understanding on bore vs stroke, the problem is The motor could max at 5000 rpms. It is the Diff gears that make the rpms at the tires....
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Vile-
I plan on running 36' super swampers, at that size I should be able to spin them like a raped ape! Some guys go too big on the tires and they get screwed. So what would be my ideal gear ratio, I still don't have all that learned yet? I of course will upgrade 3/4 or 1ton runnin gear when I get the new tires.
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I would run 4.10 if you are going with the 700R4
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700 is too weak, im going th350, and i already have a th400 to take its place.
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Look guys, stating your opinion as fact is just plain, well uneducated.
Fact #1 the 327 had the highest hp output of any naturally aspirated production gm sb engine until the 2002 Corvette z06
Fact #2 the 2002 z06 engine was a 350
Fact #3 the 08 Vette engine is 366ci
Fact #4 the 400 was only manufactured for 10 years, if it was so good why only make it for 10 years? They still made big blocks so the mpg thing is out the window.
Fact #5 the 400 was never used in the Corvette by gm which being the flagship Chevy car always got the best motors, yet the 327 was and so was the 350 as well as big blocks odd isn't it how the 350 and 327 are the 2 most popular corvette engines. I find it also interesting how during the 70's while the 400 was being produced the 350 was the base corvette motor.
Anyone ever wonder why most 400's output was around 250 hp which is around 100 hp less than the 327's? Ever wonder why gm did away with the 400?
A 400 turning 8000 rpms? On a daily driver? On a budget the OP could afford? That's a pretty big claim.
Why didn't GM bring back the 400 in the second generation small block? There has to be a reason especially with the Mustang walking all over everything Chevy made in those years.
Capt - I beg to differ with you. Getting a 327 to turn 8000 reliably is going to cost a lot less than a 400. A 327 makes 350 hp with a hyd cam, they actually call it the 350 horse 327 cam. You could drop a hyd roller cam in and get 400 hp. I think that should be all the power it would need and it can live in the 6000 rpm range all day long and be perfectly streetable, actually tame. Simple physics proves the shorter stroke of the 327 will spin faster than the longer stroke of the 400 or even the 350. The crankshaft even with no pistons attached will be capable of spinning faster. Have you ever watched a figure skater do there spin move? Did you happen to notice as they brought their arms and knees in towards the center they speed up? When their arms are out can be thought of as the longer stroke than when everything is close to the center line.
I agree that a big block is a better choice if it can be afforded because then the jump in horsepower allows you to use gearing to get those tires spinning at the right rpms. As an added benefit the bbc would still be very streetable.
1st off Chevy never did a HiPerf version of the 400 because at the time they did not know how to make it reliable in a regular driver with a warrenty, remember the 400 is a short rod engine which causes higher friction. The 400 was made for smaller lighter engine in trucks and big cars where it did its job without protest. Ask yourself this question why did Chevy make a SBC 400 when they already had the 402 BB. With today parts a 500 ft/lbs 400 with long rods is easy as falling off a log, and no 327 will ever make 500 ft/lbs at a streetable RPM and that is a fact. Torque is what moves our heavy trucks and horsepower is just a math formula. I will agree that the 327 has the greatest HP to cubic inch ratio of anything except the LS series, but torque makes a much better street driver, another fact.
Why would he build a stroked 350 when he already has a 400?
I'm gonna steal a line from my 4-yr old boy....."Because!".
I dunno, never had a 400, but, I have a 383 and that puppy has loads of torque. Torque is what makes an engine go. 'tis why they are called stump pullers. Love mine. Anyone else would love there's.
But, as mentioned, c.i.d. is boss. Go with displacement--i'm outvoted www.delbridge.net/install
383 is just a 400 crank in a .030 over 350 block, if you put that 3.75 stroke back in the 4.125 bore block where it belongs it tears up the 383. The larger bore unshrouds the valve allowing the heads to work to their full abilities.
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There has been lots of debate about the 350/400 and which can be built into a better motor. I've owned both(still do) and don't think you can go wrong with either. It sounds like your just looking to get your truck back on the road as quickly as possible. From your post in the Projects Section it sounds like you own the 400 already as opposed to the $200 350 that is shown covered in snow.
If you know that the 400 is a good motor I say bolt it in and get the truck driving again. The 350 appears to be a Goodwrench replacement motor by looking at the valve covers. Captkaos has a Link to the Car Craft buildup of this motor the Tech. Section. That could be a good project when time/money permits.
As far as the trans, your keeping the 350 but mentioned you had a 400 for it. Just keep in mind the 400 uses a different transfer case.
Like Vile said cooling can be an issue with the 400. You may want to go with an electric fan. He has a few good post about wiring them and the aluminum shroud he made for his. I mounted mine under the stock plastic fan shroud. Let me know if you need pics.
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700 is too weak, im going th350, and i already have a th400 to take its place.
Tell that to the Big Block Blazer I built 8 years ago that still has the same 700R4 behind it burning rubber all over the place. I'd build a 700R4 over a th350 any day. Having overdrive allows you to run steeper gears and get better fuel economy. Upgrading the weak links in a 700R4 is inexpensive and easy.
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I agree with you Vile, I would much rather have a 700 with OD than a 350.. Of course I prefer EFI over carbs too...
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700 is too weak, im going th350, and i already have a th400 to take its place.
. Upgrading the weak links in a 700R4 is inexpensive and easy.
What is the weak link and how much $$ is it to fix?. I swore off the 700R4 because back in the early 90's most tranny shops couldn't fix them right. Probably lots of updates for them now, and like you said before, some people just need new mechanics. How about the 4L60/241 set up from the 89-91 Blazers/Suburbans. Are they an improvement for our trucks over the 700R4/208.
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Vile- are you turning 36' or greater tires with that big block? From my understanding the 700 doesnt like it when you have to rock yourself out of a mud hole ( reverse, drive, reverse, drive) and on top of that the 700r is the most expensive tranny o rebuild, at least around here. 350's and 400 and much cheaper, easier to rebuild, and easier to find.
What do you think about my gear ratios since I am running a 350 now and will be a 400 in the future (trannys)
BTW I bought that motor last night and dropped it off at the shop. Hopefully I can pull it into the shop tonight to thaw it out, then I can do something about my truck. I might just run the 350 since it is ready to drop in, then that will let me get some cash to build the 400 up for a real mud truck.
and I prefer carburetor over efi :D
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How about the 4L60/241 set up from the 89-91 Blazers/Suburbans. Are they an improvement for our trucks over the 700R4/208.
A 4L60 IS a 700R4, same trans. In fact a 4L60E in the newer trucks is the same as a 700R4. May parts will retro back on them to the 700R4s.
Many 82-86 700R4s were junk and had alot of issues that were fixed over time. By the time you hit 88 all of them were getting the new upgrades, but earlier ones couldn't take all of them...
They gain an unfavorable rep because of the earlier models, but they are just as strong as a TH350 if not stronger.
You can build one handle 600ft/lbs before breaking under repetitive abuse.
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Capt - Can you post the parts list for that 400 build that spins at 8500 and costs less than $2000? I think the OP would love that baby in his truck and I think a lot of us might as well. I'm going 400 block shopping today are there any casting numbers I should look for and would I be running factory heads? What are the hp and torque numbers for that?
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Oh just to let you all know I voted for the bored 400 before I ever posted anything. I'm not an idiot! lol
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Capt - Can you post the parts list for that 400 build that spins at 8500 and costs less than $2000? I think the OP would love that baby in his truck and I think a lot of us might as well. I'm going 400 block shopping today are there any casting numbers I should look for and would I be running factory heads? What are the hp and torque numbers for that?
I can call him and ask him if he kept the specs. I do know he won't give out the cam specs though, which was one of the key components, he is funny like that. BTW, keep in mind the motor was built and raced when I was MUCH younger, in 1991... Any reputable shop will balance the assembly for what your intended purpose is. I had my 454 balanced to spin 8000, I used to have a video of me racing a Mustang on the street and the tach climbing to 7800rpms.
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Why is Ford an option in the poll? I vote 289. You'll love the torque. LOL.
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700 is too weak, im going th350, and i already have a th400 to take its place.
My tranny didn't get that memo either ;) The whole 327...I think I've gone there before, not going there again. Lorne
(http://i163.photobucket.com/albums/t285/HAULINIT/oldsweekend018-2-1.jpg)
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Why is Ford an option in the poll? I vote 289. You'll love the torque. LOL.
Ha!, don't forget the first mustang V8 and leftover from the Falcon, a 260. Yeah, that's the ticket. Go with a Boss 429!
383 is just a 400 crank in a .030 over 350 block
Thanks 406 Qship, I was wondering what a 383 was ;) I have to get after my webmaster for my websites for not including that info in my 383 install website (http://www.delbridge.net/install), no wait, IT IS THERE! Where's the humor in life anymore ??? (http://www.delbridge.net/chimp.gif)
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It depends on the year 700R4 which components are weak. Search my username and 700R4 and you'll find a few posts on 700R4 upgrades. Just like any trans there will be several updates over the years and the 700r4 is no exception. As far as the 700R4's reputation, well parts changer rebuilders are the ones who are responsible for that. People that had to have several rebuilds should have found a more qualified and educated transmission rebuilder. You want to find a good rebuilder? Look on ATRA's site. I am a master ATRA rebuilder, diagnostician and R&R technician, I am also a proctor for them now, I have ASE L1 Master cert, I have GM, Mopar, STG and various independent certifications for Automatic transmissions. People should find a good transmission specialist and not shop for transmission service solely based on price.
Turning 36" tires is no big deal for a properly built 700R4/4L60. I have 3 in stock I just built and one I just installed in my mutt. I have full confidence in them.
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I can call him and ask him if he kept the specs. I do know he won't give out the cam specs though, which was one of the key components, he is funny like that. BTW, keep in mind the motor was built and raced when I was MUCH younger, in 1991... Any reputable shop will balance the assembly for what your intended purpose is. I had my 454 balanced to spin 8000, I used to have a video of me racing a Mustang on the street and the tach climbing to 7800rpms.
This is what he said: "It was high compression, balanced rotatating assembly, with a solid lift cam setup really loose." He won't give out anymore info than that.
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This is what he said: "It was high compression, balanced rotatating assembly, with a solid lift cam setup really loose." He won't give out anymore info than that.
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I'm still thinking it will cost more than $2k to build any 400 to make power at 8k. First with a solid cam the lift is going to be higher than with hydraulic and even some hydraulic cams require stronger springs. Second with the amount of air required stock heads and intakes are not going to be an option. Third the bottom end is going to have to be pretty much all forged and the stock balancer I wouldn't trust at 8k. I think even a machine shop owner would have a hard time building a 400 to make power at 8k for under $2000. I also think we'd see in every hot rod magazine articles on how to build a 400 that makes power at 8000 rpms for under $2000 if it were indeed possible. Maybe your friend is overstating the facts a bit.
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Somone already said it. No replacement for displacement.
Bigger is ALWAYS better, except when the bigger is beyond the engineering.
Such is the case the 400. The bores were just to big for the block.
Leaving the 383 mod the next best thing.
Still, these are small engines. Big Blocks are always the way to go for power.
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I think the problem is you just refuse to believe it, since it wasn't published in a magazine...
You only need a number of components, Heads, pistons, cam kit, and a balanced assembly...
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Somone already said it. No replacement for displacement.
Bigger is ALWAYS better, except when the bigger is beyond the engineering.
Such is the case the 400. The bores were just to big for the block.
Leaving the 383 mod the next best thing.
Still, these are small engines. Big Blocks are always the way to go for power.
With that logic all the 4.00 bore SBC are junk to due to the reduced water circulation between the bores, and all the after market blocks that have been pushed out to 454 are junk in your opinion. There is only only thing that was poor about the 400 SBC, it is the short rods the factory used. Use the 5.7 lenght rods is an easy fix to get the friction under control. The 383 gives up power to the 400 because of valve shrouding due the smaller 4.03" bore. If the 400 is so bad why did GM use them in trucks where they would get worked like a stray dog and treated about as well. Why is it when the rules allow it the circle tracks racers will use the 400 over the 383 everytime. 383 isn't all that some would believe it to be, it can be a good engine but put all the same parts in a good 400 block and it will leave the 383 standing.
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Somebody explain something to me. If the main idea is to get maximum wheel speed, why not got with a torque monster bigblock, and gear the truck higher for the wheel speed. It takes the torque to get to the wheel speed, and horsepower to maintain right? Seems a bigblock could easily spinup some 38's and have enough horsepower at 5500 rpm to maintain it. Is this thinking correct???
If you can spin the tires on a 75 hp Pinto with 4:56 gears, then a 500 hp bigblock should be able to spin 38s with 3:73s
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Somebody explain something to me. If the main idea is to get maximum wheel speed, why not got with a torque monster bigblock, and gear the truck higher for the wheel speed. It takes the torque to get to the wheel speed, and horsepower to maintain right? Seems a bigblock could easily spinup some 38's and have enough horsepower at 5500 rpm to maintain it. Is this thinking correct???
Yep, that is correct. I said that earlier:
the problem is The motor could max at 5000 rpms. It is the Diff gears that make the rpms at the tires....
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http://www.carcraft.com/techarticles/400_small_block/index.html (http://www.carcraft.com/techarticles/400_small_block/index.html)
Nuff said.
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Somebody explain something to me. If the main idea is to get maximum wheel speed, why not got with a torque monster bigblock, and gear the truck higher for the wheel speed. It takes the torque to get to the wheel speed, and horsepower to maintain right? Seems a bigblock could easily spinup some 38's and have enough horsepower at 5500 rpm to maintain it. Is this thinking correct???
Yep, that is correct. I said that earlier:
the problem is The motor could max at 5000 rpms. It is the Diff gears that make the rpms at the tires....
Ok, I did see that earlier, but had a brain fart.
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Just so you know, in the 2002 Car Craft Real Street Eliminator contest, a huge boat of a 1982 Cadillac Fleetwood, owned by Jeff Schwartz, won overall with a hot caddy 500, a TH400, 2800 stall, 2.73's in the rear, and 26" tires. His 1/4 was an 11.80 @ 116.05.
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In my old 4x4, I ran a 406,4L80E/205, 4:10's with 36's. Here's the simple build we did for the 406.
Stock block, stock crank, main studs, 5.7 inch rod, custom forged piston, balanced, 10:1, Comp XE268H, steel Pro-Action 180cc heads with 1.6 roller rockers, Performer RPM intake, 750 vac sec Holley. Dyno'd at 392hp & 444 ft-lbs. 400+ft-lbs from 2500 up. I wheeled the shoot outta that engine, kept the rpm's under 5000, and never have had a problem. In low range it was more than enough to get the job done. I can scan the dyno sheet if you want.
Build for torque, screw the horsepower.
Off topic a bit, when I parted the truck out, I threw the engine in an ole Pontiac I was building, and being 5yrs old and abused, it still runs 12.80's @105. Done... Build away...
(http://i258.photobucket.com/albums/hh265/CSpallin/IMG_0081.jpg)
(http://i258.photobucket.com/albums/hh265/CSpallin/DSCI0014.jpg)
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I vote 377 and 5.13s ;D
Throw some big Dart heads on there and a big roller and let her eat!
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I was once told you can put a 350 crank in a 400 and make a 377 that would "run 9 grand all day"
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You were told wrong. Any SBC has to be purpose built to "run 9 grand all day".
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377 is a high revving engine, but as pointed out above it has to be purpose built. You are talking big bucks right there.
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Shame on you for crushing that malibu; It looked like it had many more miles in it.
i mean seriously.
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That's what I thought. lol. So a .30 over 350 is a 355, then with a 400 crank it's a 383 right? Then a 400 .30 over is a 406, but if you use a 350 crank it's a 377? Can you make a reverse 383?
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That's what I thought. lol. So a .30 over 350 is a 355, then with a 400 crank it's a 383 right? Then a 400 .30 over is a 406, but if you use a 350 crank it's a 377? Can you make a reverse 383?
That's all correct. But what do you mean by a reverse 383?
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400 block, 350 crank? that's a 377? so do you bore it out? I confused myself, but there's so many variables, I just wanted to clarify for myself lol!
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A 377 is technically a 400 block bored 0.030" over with a 350 crank (3.48"). IMO, for any street engine, go for cubes first. If I had a good 400 block, I would never use less than a 3.75" crank in it. Revving high is not of any importance in a street engine. Power and durability are. So 406 cubes are better than 377 cubes, period.
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Cool! Thanks for the clarification. Now I can act like I know it all in front of my friends!! lol! They're all about the b16 hondas or whatever they are. Gotta stick to my V-8s
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I love all the info but with out purpose building which would be better at stock 350 tbi or a stock 400? Used for a daily driver and some weekend mud/ bush trails.
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Depends. 350s are everywhere, the parts are available and cheap, and you can usually find stock parts salvage. It's pretty easy to get in the neighborhood of 400 ft.lbs. out of a 350, even with stock heads, if you cam it right.
That having been said, the old posts above are right: torque is what matters, and there's no replacement for displacement. The 400 can be set up for more torque than the 350 with the same amount of work.
Gas mileage in a 350 TBI will be much better than from a carbed anything, and more cubes generally speaking means more gas.
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i realize the post is 4 yrs old, but for the original application and in my opinion, i would go with the bored 350 option:
a) boring out a 400---too risky in my opinion.
b) You can get decent, NEW, stroker cranks from Scat fairly cheap---to make a 383.
Now, there is another alternative, and that is to go with a NEW aftermarket 400block, either from Gm performance parts (bowtie block) or dart etc. But this can get expensive--i think they start at around $1500.
2) i'm still not happy about the way you parked on MY malibu >:(
@ Gusgusa, i like the 350 tbi choice better for a daily driver for the mpg over the 400.
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im just going to throw this out here also. i got into a race tonight, my 2004 impala ss 3.8 s/c (240hp @5200 280tq @3200 CURB WEIGHT 3606 lbs) vs. a 1996 impala 5.7 (260hp @ 5000 330tq @ 2400 Curb weight: 4036 lbs) now the only reason i raced him was cause his tag said "THEBOSS". so after we smoked some imports we finally caught a light where it was just us two. i look over to him/her (idk he never looked my way) light turned green (in front of a state police station)
(http://www.naioa.com/v2/modules/Forums/images/smiles/lol_hitting.gif) well i didnt want to make any noise and we took off, neck and neck till i hear a squeal. i had to back off didnt want to attract any cops that might have been around. then i floored it at this point i guess he never backed off and he pulled away. no biggie i lost to a chevy ;-)
now our weight/hp ratio is about the same 15lbs:1hp. but his tq 12lbs:1tq vs my 18lbs:1tq this is the reason he won. imo even if i would of kept on it he still would of kick my but cause his displacement compared to mine. and displacement is related to tq right? so now i need to sup up my impala lol
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Hey, Irish, I think you got your rpms jumbled on the hp/torque numbers on your 3.8.
It's not just the difference in torque peak value, but his peak torque rpm is much lower too, so he's into his torque curve a lot sooner.
It's the cubes that give him the torque.
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Thanks I think I wil go with the 350 tbi and put some work into it. Seems like the better option for me.
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sure did rich thanks don know why i didnt catch it even when i reviewed it and added lol. and that is why i added the rpms. it wasnt all about the motor size or numbers. but more how it is built. if you look back at rich's post about building a engine he will always add its the tq not hp. if you build a motor with low tq you can take off like crazy you might lose the top end but you can haul stuff and not have a problem taking off
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Yeah, one thing about building for torque and not top end is you may have to adjust your WOT shift points, but I should have a post on this coming up this week. Still working the solution, but I anticipate having some interesting stuff to report later this week.