302 heads aren't worth putting money into. Magnum heads would have been a good bang for the buck.

Are the 302 heads better than the 69 heads? Yep, but not enough better stock for stock to warrant the costs of the gaskets to swap them and putting more money into them to improve performance is worse costwise.

A cam swap would perk either set of heads up though. I like the 340 cam in a street 318 myself.