The first one I tried told me that a flat top 350 with 64cc heads had like 12.4:1, which I know is wrong. I don't necessarily trust that engine calculator. I found my 32s 462' Buick engine - with mild cam - idled at 18.5' at 350 altitude and here in Sunny Arizona at 3350 altitude it idles at 16' of vacuum. Big cam, say 280 degrees + advertised duration, vacuum will be 9-11'. Edelbrock Performer 454 TBI intake manifolds deliver outstanding.

Flat tops with four valve reliefs are usually around -5cc's. This is a common problem with the Edelbrock version of the AFB. I also use 350 Cop Car injectors at about 13 PSI, with the 350 injector pod / fuel. Usually the low compression engines have dished pistons that would yeild lower compression. *notes: I've never heard of -7cc pistons. If you were to go with Vortec heads, either get the ones that have been upgraded to allow for additional lift, or be very careful not to exceed the max for those heads. Put that same cam into a 520-inch, 12.5:1, dual-quad, CNCported high-riser-head combination and you get up to 771 hp at 6,900 rpm, along with torque of 653 on the same dyno. With the iron Vortec heads' chamber design, you may be able to, as well. With an 11:1-compression 482 and ported Edelbrock heads, this cam is good for a bit over 610 hp at 5,800 rpm, along with 620 ft-lbs of torque. Then I changed the combustion chamber cc's to 64 to see what a head swap would do to your compression, It was 9.6:1.ĩ.6:1 Aluminum heads, you will still be able to run 87 octane. Gasket thickness (including deck height)=.

I used a calculator I found online with a google search, and typed in numbers until I got a 350 with 8.5:1 compression.

Big cam 350 edelbrock problem