which heads on a 318

I have both 302/675 318 heads and I also have a flow bench, the diff between the 2 is the closed/heart shaped chamber on the 302 heads.

You can easily achieve 300+hp with stock'ish heads, and those stock'ish heads ported go into the 200's fairly easily.

I ported 1 intake port and compared it to the stock port, big diff from with it going from a stock 160's cfm to 200cfm, the exhaust has tons of meat and will make 140's cfm real quick, thats 360 head flow right there but without the large everything that comes with them, but like rumble said...depending on the rpm/usage 'to be general'...the 360 head does have the volume offering to higher rpms and the 'just bolt it on and go' appeal when the rest is matched.