73-87 Chevy _ GMC Trucks > Performance
Crate Stroker or 350 upgrade?
mattevandavis:
I have a low mileage used 350 GM 195 HP motor (8.5:1). I've been debating upgrading the cam and heads, possibly bumping it to a 383 or selling it and picking up a 383 mid dress. This woudl be for my 73 C10 W/ SM465.
Budget wise i'm obviously not opposed to the cost to the crate motor, but I do want something that is street-able if not daily driver ready.
So thoughts, opinions, comments?
Keep Stock Motor
Option 1
$2500
trickflow aluminum or dart steel heads
Howards MC112011-11DL or Comp 12-234-2 cam
engine work bearings etc
etimated 350 lbs-ft
Option 2
$3500
Add Eagle 383 stroker
estimated 400 lbs-ft
Crate Engine
$3700
ATK HP94
470 lbs-ft
75gmck25:
Last summer I upgraded my 350 with Blueprint aluminum heads and a Howards Retrofit Roller CL110235-12 Cam kit (213/217 @ .050). The result should be about 325-330 HP with my stock exhaust manifolds, and should probably run about 350 HP if I had used headers. It runs about 17"-18" of idle vacuum, and pulls smoothly on the street (slightly rougher idle than stock).
Everything went well, but I spent a lot of time hanging over a high 4WD engine compartment getting all the parts installed. The total bill was more than I expected because I chose to make other upgrades (full roller rockers, which needed tall valve covers, timing cover with adjustable cam button, etc.). In retrospect, it probably would have been easier and just as cost effective to buy a new crate Vortec 350 for about $2,600 and replace the entire engine. Or buy a crate 383 at 430HP/450 torque for $4,000. Even the upgrades would have been easier if I had pulled the engine and did it all in the garage.
Its hard to get the old 350s up to a good compression ratio if you don't change pistons. Most of them run closer to 8.2 compression, and the 64cc heads add about 1 point of compression. I used a thinner head gasket to get about .2 more, but that still only gets me up to about 9.5.
For the cam you listed, 9.5 compression should be find, but for higher lift cams (for example, 224-228 @ .050 and up) you really need closer to 10.0 compression to make it work effectively. Big cams and low compression don't work together well. I also strongly suggest using a roller cam, and preferably with a roller-ready block to make installation simpler.
I learned a lot by adding parts to the old engine, since I had to research all the combinations of parts, and I was was doing all the wrench work myself. However, buying a new crate with a nicely matched set of parts is also a great solution.
Bruce
Irish_Alley:
http://forum.73-87chevytrucks.com/smforum/index.php?topic=32168.msg271442#msg271442
read that, they talk about buying a gm crate motor 260 for around 2k and swap cams to push 290/420.
mattevandavis:
--- Quote from: 75gmck25 on March 06, 2019, 06:06:39 AM ---Last summer I upgraded my 350 with Blueprint aluminum heads and a Howards Retrofit Roller CL110235-12 Cam kit (213/217 @ .050). The result should be about 325-330 HP with my stock exhaust manifolds, and should probably run about 350 HP if I had used headers. It runs about 17"-18" of idle vacuum, and pulls smoothly on the street (slightly rougher idle than stock).
Everything went well, but I spent a lot of time hanging over a high 4WD engine compartment getting all the parts installed. The total bill was more than I expected because I chose to make other upgrades (full roller rockers, which needed tall valve covers, timing cover with adjustable cam button, etc.). In retrospect, it probably would have been easier and just as cost effective to buy a new crate Vortec 350 for about $2,600 and replace the entire engine. Or buy a crate 383 at 430HP/450 torque for $4,000. Even the upgrades would have been easier if I had pulled the engine and did it all in the garage.
Its hard to get the old 350s up to a good compression ratio if you don't change pistons. Most of them run closer to 8.2 compression, and the 64cc heads add about 1 point of compression. I used a thinner head gasket to get about .2 more, but that still only gets me up to about 9.5.
For the cam you listed, 9.5 compression should be find, but for higher lift cams (for example, 224-228 @ .050 and up) you really need closer to 10.0 compression to make it work effectively. Big cams and low compression don't work together well. I also strongly suggest using a roller cam, and preferably with a roller-ready block to make installation simpler.
I learned a lot by adding parts to the old engine, since I had to research all the combinations of parts, and I was was doing all the wrench work myself. However, buying a new crate with a nicely matched set of parts is also a great solution.
Bruce
--- End quote ---
Thanks for the good info.
If I dont buy a crate motor i will shoot for 9.5:1 as well. The motor is out of the truck so no late nights of leaning in over the top of an engine while i wrench. Not until it goes in any way.
Still learning a lot about SBC. I've built 4cyl fi motors with a boat load of sensors and computer tuning. It took months to find the combo i felt good about and there were about 1/10 of the choices for sbc. Once i wade through the choices i still have to learn to be a real mechanic to get it all running right. Luckily i will have help.
I like the crate motor for a few reasons:
1. Proven combos - not trying to find a magic combo based off of vauge information from dealers
2. No machine shop needed. I have had a time finding quality shops and had work done more than once on 3 motors. Each at a different reputable shop.
3. Less likely i make a mistake during assembly. Been bit by this one too and spun a rod as a result
4. Warranty. This is probably wool over my eyes but its nice to think id have a 2(+) year warranty.
Im looking at ATK and Blue Print. I know everyone has different opinions but Summit Racing sells them. I figure they are probably as good as anything i can build and Summit is in my backyard.
The major benifit to using the current motor is the enjoyment. I cant say it would be less money, budgets creep up quickly especially when you find out you need a new tool.
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mattevandavis:
--- Quote from: Irish_Alley on March 06, 2019, 08:11:13 AM ---http://forum.73-87chevytrucks.com/smforum/index.php?topic=32168.msg271442#msg271442
read that, they talk about buying a gm crate motor 260 for around 2k and swap cams to push 290/420.
--- End quote ---
Thats a good read. If i dont go 383 im thinking more and more about the XE250. Runs out of breath around 4800 but im going to do some light towing and street driving not racing. 420 ft-lbs isnt quite 470 but it would come at $2000 less.
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