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73-87 Chevy _ GMC Trucks => Performance => Topic started by: 76K20 on March 09, 2015, 11:04:43 am
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I have a 350, 1977 corvette motor, 8.5/1 compression, 4 bolt mains, 180/185 horsepower. I'm thinking of building it for a torque motor. Putting it in a 76 3/4 ton 4.10 gears with a 350 automatic. The truck is a daily driver through the week, hauler and tower on weekends, camper and wood/coal, with some trips as much as 250 miles one way on the weekends. Looking for suggestions on how to go about this build. What say you guys with more experience than me? Thanks guys. Alan
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Qjet from SMI on a dual plane Edelbrock 2101, a Comp Cams 12-300-4 or 12-230-2 cam with matching lifters and springs, Hooker 1453 (for 4WD) headers, and 2.25" duals out the back through some free-flow mufflers (I have FlowMaster 40s), with a 2" H-pipe under the tail cone of the xfer case. 420 lbft of torque at 2500 rpm, about the most you can get out of a 350 for reasonable money. For torque there's no need to replace the heads or up the compression ratio, which you would do for high-end horsepower, but heads and machining are a lot more money than a cam with new lifters and springs. The 12-230-2 will have 290 hp at 4000, but is higher lift, so more wear and tear on the valve train and lower engine life. The 12-300-4 will have 275 hp at 4000, but it is stock lift and is the more conservative build for engine life.
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Qjet from SMI on a dual plane Edelbrock 2101, a Comp Cams 12-300-4 or 12-230-2 cam with matching lifters and springs, Hooker 1453 (for 4WD) headers, and 2.25" duals out the back through some free-flow mufflers (I have FlowMaster 40s), with a 2" H-pipe under the tail cone of the xfer case. 420 lbft of torque at 2500 rpm, about the most you can get out of a 350 for reasonable money. For torque there's no need to replace the heads or up the compression ratio, which you would do for high-end horsepower, but heads and machining are a lot more money than a cam with new lifters and springs. The 12-230-2 will have 290 hp at 4000, but is higher lift, so more wear and tear on the valve train and lower engine life. The 12-300-4 will have 275 hp at 4000, but it is stock lift and is the more conservative build for engine life.
Some days I swear you need to be called a parrot.
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Qjet from SMI on a dual plane Edelbrock 2101, a Comp Cams 12-300-4 or 12-230-2 cam with matching lifters and springs, Hooker 1453 (for 4WD) headers, and 2.25" duals out the back through some free-flow mufflers (I have FlowMaster 40s), with a 2" H-pipe under the tail cone of the xfer case. 420 lbft of torque at 2500 rpm, about the most you can get out of a 350 for reasonable money. For torque there's no need to replace the heads or up the compression ratio, which you would do for high-end horsepower, but heads and machining are a lot more money than a cam with new lifters and springs. The 12-230-2 will have 290 hp at 4000, but is higher lift, so more wear and tear on the valve train and lower engine life. The 12-300-4 will have 275 hp at 4000, but it is stock lift and is the more conservative build for engine life.
^ This sounds like a pretty good recipe! The only thing I would do differently is with the exhaust system. I understand exactly the reasons for the 2 1/4 exhaust. However, since this is a 3/4 ton and MAYBE the owner finds a big block cheap in the future, I would go with a 2 1/2 exhaust. I also have the Flowmaster 44's on mine and I really like them as well.
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Qjet from SMI on a dual plane Edelbrock 2101, a Comp Cams 12-300-4 or 12-230-2 cam with matching lifters and springs, Hooker 1453 (for 4WD) headers, and 2.25" duals out the back through some free-flow mufflers (I have FlowMaster 40s), with a 2" H-pipe under the tail cone of the xfer case. 420 lbft of torque at 2500 rpm, about the most you can get out of a 350 for reasonable money. For torque there's no need to replace the heads or up the compression ratio, which you would do for high-end horsepower, but heads and machining are a lot more money than a cam with new lifters and springs. The 12-230-2 will have 290 hp at 4000, but is higher lift, so more wear and tear on the valve train and lower engine life. The 12-300-4 will have 275 hp at 4000, but it is stock lift and is the more conservative build for engine life.
Some days I swear you need to be called a parrot.
???
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BTW, that should be Hooker 2453 headers. I knew that, mis-typed and didn't spot it.
I don't get the parrot thing. The forums get the same question a lot -- how to build a torquer engine -- and when we do, I give the same answer every time. But I'm not "parroting" someone else. My own goal with the current setup was a torquer engine. I had the stock engine, I replaced it with the 350/290 crate engine, which sucked in a truck, then I re-cammed that with the 12-300-4, which is the about the most torque you can get with stock lift. And that worked out great, and I couldn't be happier.
The advantage of my answer is that it isn't a "Well, on my next build I think I will go with" build, or a "I know this guy and what he did is" build. It is in fact what I did, with the same goal as the OP, and I know it works and is within the scope of most guys working in their garage.
If someone asks, "What should my build be to get 400 HP?", I don't have a good answer, and so I won't offer an answer. But when someone asks how to build a torquey 350, that I can answer from my own experience. No parroting.
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Thank you Rich. That is what I was looking for someone who has already done it. BTW why not a Holley or Edelbrock carb?
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Qjet from SMI on a dual plane Edelbrock 2101, a Comp Cams 12-300-4 or 12-230-2 cam with matching lifters and springs, Hooker 1453 (for 4WD) headers, and 2.25" duals out the back through some free-flow mufflers (I have FlowMaster 40s), with a 2" H-pipe under the tail cone of the xfer case. 420 lbft of torque at 2500 rpm, about the most you can get out of a 350 for reasonable money. For torque there's no need to replace the heads or up the compression ratio, which you would do for high-end horsepower, but heads and machining are a lot more money than a cam with new lifters and springs. The 12-230-2 will have 290 hp at 4000, but is higher lift, so more wear and tear on the valve train and lower engine life. The 12-300-4 will have 275 hp at 4000, but it is stock lift and is the more conservative build for engine life.
Some days I swear you need to be called a parrot.
i think/hope what he meant was you have the same answer for everyone who ask about how to build a 350 for high torque.
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Yes exactly lol.
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lol at first glance i took it one way, then after reading what rich posted i thought about it and took it another
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but anyway back to the engine. how much money do you want to spend? have you thought about a 383 or building one? nothing wrong with what rich posted but just want to give you other options
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but anyway back to the engine. how much money do you want to spend? have you thought about a 383 or building one? nothing wrong with what rich posted but just want to give you other options
Trying to keep it as low budget as possible, but always open to options. What would the advantage be to a 383?
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383HT with headers will get you about 330hp and 430lbft, for $4500.
Story about that. A friend was building a house, and was shocked to find that an 80-gallon water heater was like four times as expensive as a 40-gallon. All things being equal, it should be cheaper than doublel. It's easier to build one of something that's a bit bigger, than it is to build even two of the regular one. What gives? Because the 40-gallon is the standard size, they crank them out like potato chips. With those volumes, it pays to optimize the design and manufacturing to the nth degree. And there's a ton of competition in the dealer network in that size. At some level, the 80-gallon is a specialty item, and the 40-gallon is for everybody else. I told him to have them install two forty-gallon units in series, and plumb in a bypass on both. That way, it was less than a single eighty-gallon unit, and he had the benefit that when one fails, he can bypass it and still have hot water until they can come replace it.
Anyway, the base 350 crate is the engine that they sell a canful of, and everything else is basically a low-volume specialty item, so they are much more expensive for what you get.
enaberif and I are both on another of the forums for square bodies, and I gave basically the same answer to basically the same question over there today. Hey, at least it's the same answer! Giving a different answer to the same question, now that would be weird.
I have an Edelbrock on mine, not a Qjet, because the Edelbrock was brand new on the truck when I bought it, so basically it was free and anything else cost extra, and I had other expensive things that needed doing on the truck. My take is that the Holley is a better track carburetor -- it's what my drag and circle-track buddies use -- the Edelbrock is OK, and it's simple and easy to tune, and the Qjet is more advanced technology than the Edelbrock, gives better gas mileage and throttle response -- is all around the best street carb -- but is more difficult to tune, which is why I think getting one from Sean over at SMI custom tuned for a given setup is the way to go. When the Edelbrock dies, that's what I will do.
My own build is:
- GM crate 350/290 re-cammed with a Comp Cams 12-300-4 (which is the same as a 350/260 re-cammed with the 12-300-4, because the cam is the only difference between the 350/260 and 350/290)
- Edelbrock 1406 on an Edelbrock 2601 dual-plane, air-gap Performer manifold, with hot- and cold-air induction (The Q-jet is my preference, but as I said, the new Edelbrock was on there when I got the truck. The Q-jet will be the replacement when the time comes. The 2601 manifold is the air-gap version of the 2101, which has advantages, but you can't use it unless you keep the thermac air cleaner setup.)
- Hooker 2453 headers through 2.25" duals with FlowMaster 40s, and a 2" H-pipe under the tailcone of the xfer case.
- Flexalite electric fan in front of the radiator and Flexalite controller, which allowed me to lose the shroud and the fan on the engine, and also gives me mucho heater in the winter because I can hold engine temp. Also better gas mileage in the winter. I get the same mpg in any weather.
(http://users.rcn.com/weyand/smalls/imag0766small.jpg)
(http://users.rcn.com/weyand/smalls/imag0431small.jpg)
(http://users.rcn.com/weyand/smalls/imag0314small.jpg)
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he was talking about building an engine from what i remember to build a 383 is about 2k. it was years ago we looked into this but i think it was 700 or so for machine work and 700 was a cheap kit you could buy for the 383. this was years ago and i dont remember the details would have to look into it again but rich how much to you have into your engine build?
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he was talking about building an engine from what i remember to build a 383 is about 2k. it was years ago we looked into this but i think it was 700 or so for machine work and 700 was a cheap kit you could buy for the 383. this was years ago and i dont remember the details would have to look into it again but rich how much to you have into your engine build?
The fast way to where I eventually got is the GM 350/260 crate motor ($1450) plus the cam (about $120).
I bought the 350/290 for $2000, suffered with it for a year, then had the cam changed out, which was $120 for the cam, plus a lifter kit, plus about $1000 labor to change it out with the engine in the truck. They had to strip the top down on the engine, pull the cam out the front, then put it all back together, so I had that shopped out. Sometimes I have more money than time, and it is my daily driver.
And you're right, the OP asked about building an engine up. He already has the (used) 350/260 engine, so rod and crank bearings, piston and bore work, rings, lifters, cam, and rebuilding the heads are all on the table already. I would budget all that carefully, and compare it to the price of going all new with the 350/260 crate engine and a new cam.
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The story has it this is a Jasper rebuild with around 15,000 miles on it and supposedly has an "RV" cam in it. I have not heard it run nor pulled it apart yet. At the very least I want to pull the heads and oil pan to look things over and plastic gauge the bearings.
but figured while I had it apart.....
Are aftermarket cams stamped any way to ID them? Or how can I tell what cam is in it?
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This was just the thread I was looking for. I'm wanting more torque in a 350 3/4 ton also. Thanks for starting this thread and for the positive posters. I a big believer in learning from more knowledgeable people. It saves one time and money coping from others more in the know. Thanks, Ken
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I like the 383 idea as well.
If building a 383 from a 350 there are reasonable priced cast iron 3.75" cranks available.
Pistons are available to use 350 rods with the longer stroke.
In addition to the above quoted specs for cams, etc. you may look at throwing on a set of 1.6:1 ratio rocker arms. They give a slight amount more lift without the extra duration penalty.
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I started with a '92 350 4 bolt main block with the factory roller lifter setup. I use 6.0" rods with flat top pistons with about 9.8 compression. I also use roller rockers, an electric fuel pump, and an electric fan. It has a Comp Cams 08-410-08 set to 4 degrees advanced, a gear drive, and Sportsman heads with 2.02 and 1.60 stainless steel valves. It's capped with an Edelbrock Performer, either a 670 Holley Avenger or a 600 Edelbrock AFB style, and a MSD distributor and box. It's in my '81 K20 with 4.10 gears. I've pulled a 3 horse goose neck trailer with 2 horses 75-80 mph on the interstate. A similar crate motor was rated at 375 ft-lbs of torque. You can get a better lobe profile with roller lifters. If you reduce the internal and external friction, then the 350 can start to have torque that you can feel in a 3/4 ton truck.
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Regarding the pictures:
Is there any advantages/disadvantages to putting the fans IN FRONT of the radiator as opposed to behind?
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The disadvantages are serious:
- It gets in the way of doing airconditioning.
- It is not as effective, because if you try to shroud it, you just block airflow, whereas shrouding the fan on the back side collects all the frontal surface airflow and uses the whole radiator. This is by far the most effective cooling strategy.
- The fan is now exposed to tossed rocks and the like.
The advantages of putting it in front of the radiator is that it gets the rotatey finger-shreddy part out of the engine bay and gives a very clean look.
The only reason I can get away with this is that I don't have air conditioning and because my engine setup runs very cool, even cold. Even with the setup I have with the fan in front, in the winter I have to cover the grill or I can't get the engine up to temp.
But I certainly would not do this with a bbc or a high-compression engine.
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If you want torque use a comp extreme 4x4 cam 12-235-2 my 355 with flat tops 4 valve relief hyperutecnic pistons 882 heads edelbrock performer and edelbrock 1405 carb with metering rods changed is a torque monster !
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If you want torque use a comp extreme 4x4 cam 12-235-2 my 355 with flat tops 4 valve relief hyperutecnic pistons 882 heads edelbrock performer and edelbrock 1405 carb with metering rods changed is a torque monster !
Uh, yup. That's another one of the good cams for these engines.