302 heads

Since you're going with 302 or 741 heads.. you might as well go with hydraulic roller cam. The heads are already have big push rod holes and retrofit lifters are cheap now. It might save you some headaches with cam break in. A little port matching and Bowl job and a bigger valve will help. Be sure to look out for valve shrouding. All that being said Magnum swap will make more power but cost more.