Matt, my dad runs 1969 302 heads on his 1975 351W we currently run in our truck. the heads were milled for 9.5:1 compression on dished pistons with 2.02/1.6 triple ground valves, hardened valve seats and a 3 angle valve job with full porting on both sides. The head bolt holes in the heads needed to be drilled to 1/2". It is not difficult to do.
They run very well.
GT40 and GT40P heads are also excellent but the P heads have a revised spark plug angle which you need to buy specific headers for.