Top End Performance Upgrades 350 chevy

[chevy_guy]

I bought a 79 chevy custom deluxe with a 350 4 bolt main and 700r Tranny. When I bought the truck I didnt know what type of shape it was in so I tore it down and had the heads block and crank checked for any issues and it all came back clean without any abnormalities. Now time for Upgrades. I would like to gain as much HP/Torque as possible without replacing the heads. This leaves the cam (possible a kit with pushrods and lifters), intake and carb. Now I have read that the max lift on stock heads was .500, and when choosing a cam they have the advertised lift listed in the specs, is there anything else I need to look out for when picking a cam as to not damage anything in the engine. As for the intake, I am looking at a dual plane design I like the Air-gap design that Edelbrock offers on it performer Air-gap or its performer rpm air-gap, both of these are nice. Are there any issues with these that I should know of ie...hood clearance. When choosing a carb I am thinking about the holley ultra street avenger 670. IS this enough cfm for  the setup im looking for? All suggestions welcome.

[Chris9450]

I'll chime in here and try to give you a hand. I'm by no means an "expert" engine builder, but I'm on my 2nd SBC build up and I've overcome some of the hurtles you are having.

I have the Performer Air Gap. It's a great intake. The only difference between a Performer Air Gap and Performer RPM Air Gap is the power band. The RPM is 1500-6500 RPM whereas the Performer is idle-5500 RPM. Generally speaking, ~5500 RPM is the red line for a stock bottom-end SBC, so the Performer Air Gap would probably suit you best.

When choosing a cam for stock heads, ideally you wouldn't want to go over ~90% of the max lift of your springs. You would do well with a cam around a .450 lift. Duration is up to you. In a nutshell, a higher duration cam will give you more of a "lopey" idle and more power on the top end. A low duration cam will give you more of a "smooth" idle and more power at the bottom end. The higher duration you go, the more other components come into play (compression ratio, torque converter stall rpm, rear end differential gears, mileage, etc).

It's difficult to make a camshaft recommendation based on the information in your first post. There is a lot of information that you would have to take into consideration when choosing your cam. If you have any further information I would be happy to help you further.

Chris

[79brent]

CFM = (RPM times CID) / 3456__off the net.v.

This equation will give the required CFM for a multi-cylinder four-stroke internal combustion engine consisting of at least four cylinders (it may be used for fewer cylinders, with modifications) and a common plenum area for the intake; with a volumetric efficiency of 100 percent.

557CFM=(5500x350)/3456. I imagine the 670 would work fine for you and you have room to grow if you do more upgrades down the road. There is a member on here with the 670 and vortecs making 400hp.