302 heads have two things going for them.....they are high compression heads (usually 69cc) and they have the heat treated valve seats for the newer fuel (gas). They also have larger exhaust ports relative to 318 heads. So I don't see any draw backs???
I put them on my '69 318 and they have worked out great!!!
3 things! quench pad,..can run a point to point and a half higher compression with out detonation but requires getting piston .040 from quench pad...0 deck .040 head gasket....magnums got 2 quench pads, but no shaft rockers!