mine is a gen V all gen V VI have 4 bolt mains the 330 has small oval port heads little valves, cast crank and pistons. I was able to put gen IV heads on my gen V you have to watch you have enough material on the block and head around the water jacket so you won't get water in the oil. It is a true that a set of large oval port heads with big valves flowed and ported will make some power.

dean had a poblem with these aholes not standing behind an engine they built that had a problem, id keep looking instead of dealing with these bozos