Thread: Questions about SBC 350 build up

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I just finished putting my 350 back together, but don't have access to a dyno. Based on this information, and your experience can any anyone give me a ball park figure of how much horse power the engine is going produce.

1970 350 4-bolt main stock block bore 0.30 over
Flat top pistons
Compression 10.5:1
Vortec Heads casting #12558062 (stock)
Comp Thumpr cam CS 279T H-107 Duration @.006 tappet lift 279/297 Gross valve Lift 479/465
power range (2000-5800)
Edelbrock Vortec High Rise Air gap Intake P/N 7516 power range (1500-6500)
Street Avenger Holley 670 cfm carb
Accel performance distributor w/ HEI super coil

Thanks for any feedback or recommendations you can provide

Hard to say without a few more specifics. Was the block zero decked and squared to get a true compression ratio of 10:1, or are the pistons laying down in the holes? Was anything done to the heads, better springs, a bit of match porting, or? Lots of duration on that cam, way more then you probably need, was it degreed to verify the centerline or just put in and set with the marks? Good headers or some little peanut tube `1 1/2" block huggers?

If I had to guess, I'd say probably the 340-360 horse range.... If work I mentioned was done, plus a lot of other goodies that the engine builders like the guys we have on here (Pat and Jerry) do things, then a cam that would work in sync with the rest of the engine, you'd probably be nudging the 400 horse level.....

There are dyno syms you could do a search for to plug in your info that will give you a ballpark number.

Thanks guys that's the feedback I need, Dave you mention the cam duration is a little much, which cam would you recommend with current setup? I used the recommended Comp cam valve springs. The Deck Height: 0.20, Gasket thickness: 0.40, Combustion Chamber 64cc. There was no machine work done to heads and the cam was not degreed to verify centerline

Your numbers are off----decimal points??? wrong place?
cam duration numbers should be at the .050 spec---

Probably less than 300hp

My guess would be around 340-350 hp. Thumper cams do not make as much power as other cams of similar size (e.g., XE 268). But like Dave said, a lot of it depends on how all of your components work together and how well tuned it is.

Cam selection is dependent on so many other things...vehicle weight, converter flash rpm, gear ratio, etc, etc. I use the Cam Quest 6 software, then come back here and post it for the engine guru's, then go through the whole thing again with one of the techs at the cam companies--usually Comp or Lunati, and that's just because I've been able to go fast with there stuff before... I'm sure all the other cam companies are equally good.....

I think a primary question here is what are your goals??.

My initial goal to was build a solid 400 horse power engine. Nothing radical, but have enough power and torque to put a few of the muscle cars in my review mirror. But in addition to that I would like the engine to perform well around town as well as on the highway. Is it possible to reach that 400hp range with current setup already mention in thread, and some machine work on heads and a different cam?

Possible????? well----

Look at these dynoed combinations. This site should give you some idea as to what hp and torque certain combinations produce.

Ryan's Small Block Chevy Stroker Engine Combo Page