So I have a tall deck 8.0L bbc as advertised by gm industrial. Mine was in a generator made by Generac and has some interesting parts. Scat crank, nice rods, speed pro flat tops, 1 piece rear seal. It looks new inside (ran on propane?) My question is about the heads. They look like a "fastburn" style chamber and has the 2.06/ 1.725 valves. I haven't cc'd the chambers yet. The only casting # is a Generac p/n. They look like oval ports. Im going to try to get 600 h.p. naturally aspirated from this combo. Do you think I can do it on these heads with some port work?