I could put more compression in my 470 but then I need to run race gas. I'm at 750 with pump gas and the stock block probably doesn't want to see more than 800 hp so I'm thinking there is no reason to try it.

I could put the 270 heads on my 514 engine and see what happens. That engine is 15:1 with the EZ heads. I think the 270 heads would fit on there but I'd have to double check the dome clearance since the combustion chambers are a little different. I'd need new valve springs since the 481 lobe with the 1.65 T&D rockers is about 0.800 gross lift. I think the 270 heads have enough valve length to handle 800 lift so that shouldn't be a problem.

Be interesting to see what would happen though. The engine makes 900 hp with the EZ heads but I don't think it would make that with the 270 heads. Probably drop at least 50 hp, maybe more.