I have a freind that has just aquired a 65 skylark with a 300 4 barrel that would like to use a good set of 340 heads on it. Does anyone know if this interchange is possible? 300 block, 340 heads, 300 intake? Also is there a difference in combustion chambers between 300 and 340 heads that would change the compression ratio?
I don't believe the heads will interchange, but I may be wrong. I do know that you will need to use 340 intake with 340 heads. A 300 intake will not fit. Been there, done that trying a 340 intake with 300 heads. Good luck.
the heads, timing cover, oil pan, valve covers and exhaust manifolds all interchange on 300-340. also the distributor and all brackets. the reason the intakes do not interchange is because the deck heights are different meaning that a 340 uses a wider intake than a 300 and a 300 intake will not fit a 215 for same reason
