307 heads on a 350

Okay, my friend just called from back home and said he found a set of 307 heads for 50$ with 1.72/1.50 valves. My question is would it be better to go with these and have bigger valves put into them or to use my 624 big chamber, big valve heads? I have a 268XE cam with .477/.480 lift at 224/230 duration at 50. The engine will have around 8.5:1 cr with the big chamber heads and the 307 heads would give it higher compression since they have smaller chambers. My two bigest problems with the 307 heads is the size of the runners and also cost of putting in bigger valves. What is our opinion? Also, i'll post casting numbers when/if I know them and whatever info I can find on them.


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the 307 heads had 74cc chambers compared to the 76cc the 624`s have, so you won`t notice a power increase, I wouldn`t waste money on the 307 heads, I can understand how the budget works, almost everyone`s on a budget, I`d say get some good heads to start with and you`ll be money ahead.

Ditto to what doublevision said. The small ports of the 307 heads won't come close to the breathing of the 624s, not worth the time, effort or money.

yeh thats what i thought, thanks alot guys