Originally Posted By Michael Ecks
If you are want to put it on a 318 you should gasket match the heads or run 340/360 heads or else you'll have port mismatch in a direction that will affect performance.


Not on a mild 318 it won't.

This old chestnut gets pulled out whenever anyone want to put a 4bbl intake on a 318. If you are actually building the 318 to the point that this issue rears it's head you are building the WRONG [censored] engine. You should be building a 408 not a 318.

They say there are no such thing as a stupid question.
They say there is always the exception that proves the rule.
Don't be the exception.