Hey guys, this past weekend i picked up a really nice 351w short block at the swap meet and plan on replacing my 302 with it. I heard I can use my 302 heads if i drill out the holes. However, i would rather get some with better air flow. Im not sure if it would be better (or cheaper) to just take them to a machine shop and get them ported and stuff or just buy some fancy aftermarket ones. Any advice?...