Joe King

I have a set of stock pull off 7a heads and a set of 8 heads which have been ported, dish areas has been polished and valves have been grinded. I do not know how far they have been shaved but measuring the chamber depth, the #8 heads are deeper (not much) than the 7a heads. Both sets of heads are running the same stock size valves. Trying to decide which set I would be better off using. I planned on using the 8s but now that I have the block back from machine shop and it is almost go time to start assembling the engine I am on the fence. The option really are the way they sit. No more funds to Port the 7a heads.

The rest of the engine is bored .040 2cc pistons, rv cam with an Edelbrock performer (non rpm) intake, headers and is replacing a 307 in a Cadillac.

svnt442

It sounds like the 8's would be the way to go.

AZ520

# 8 shaved some more or get the thinest gaskets you can find, cometic?

olds 307 and 403

If the exhaust bowls had a bowl hog used on the #8 heads, they would equal the 7a for flow, we are talking 1972 350 heads correct? With a 2cc dish piston, even if a clean up mill was done, you should be around 9 to 1 with #8 heads. Assemble it, see how far the pistons sit down in the holes and cc a chamber before you buy head gaskets. I have found #8 heads measure 77-78cc untouched but yours have polished chambers and have probably been milled.