302 vs 351 heads: While 289/302 and 351 cylinder heads are essentially the same, there is one small difference between production versions. 351 blocks use 1/2" head bolts, while 289/302 blocks use ...

cylinder heads from a 351, High-Rise Aluminum Intake Manifold, and a Holley four-barrel carb, the Boss 302 could actually pull closer to 350 or even 374 hp according to some dyno tests.