Thread: Vette motor heads

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I bought '76 Corvette 350 to rebuild and it has the 882 heads which seem to be the lowest form of performance head according to flow measurements. See

http://chevyhiperformance.com/techarticles/41598/

I had my heads rebuilt with a three angle valve job and the heads planed down to a 73 cc volume along with a professional smoothing of the exhaust ports. After all was said and done I spent about $500 on the heads so in hindsight it probably would have been better to buy new Vortec heads for about $550, but I will run what I have for while. If you are going to upgrade the intake anyway it is no big deal to buy the intake for the Vortec heads. My question to other folks on the forum is what was the most restrictive part of the low HP numbers of the '74-'76 Corvette 350s? I have the lowest of the lowest originally rated at 160 HP with a two-bolt main block, but even the four-bolt block only put out about 210 HP. If the 882 heads flow well at low rpm what is the choke condition on the rest of the engine, the EGR intake? The original Rochester Quadrajet was rated at 750 cfm (I think) so that should not have been the restriction. What about the cam? Maybe the main problem was the detuned cam? I am using only a Crane blueprint of the 300 HP cam (flywheel) from the earlier 350 and I am hoping for low rpm torque for the OD trans at low rpm but hopefully more than 160 HP! Anyway from the flow data at the site given above the problem is not at the head ports so maybe with a better cam you can improve that Corvette 350. If you check out the Chilton's listing of the HP numbers for the Corvette from '70 to '80 you will be amazed at how detuned the 350 was. I was also very disappointed with the cheezy plain tin valve covers on my two-bolt 350 but I'll live with slightly less cheezy chromed tin covers!

Don Shillady
Retired Scientist/teen rodder