Well on the motor I ran last year I had a set of 1969 Boss 302 Heads with the really big valves in them 2.250 int. 1.820 Exh. That motor ran really good an put out 658 H.P.
Now this Year I built my new Motor with a set of Boss 351C heads with the Exhaust port plates put on them with lots of porting done to them. These plates are the ones where they mill the heads and attach the plates that raise the ports 1" and really help them to breath.