Aren't we facing a CSA issue? And maybe what we are seeing when keeping the top ends the same is how hard the bigger cubes are working the induction system? Kinda why I asked what the heads were for. Put a max effort 408 top end on a max effort 360 and watch the power numbers come much closer or eclipse the 408 as the rpm capability is increased vs a smaller head setup for a 360. The guy building the his version of a max effort 360 may not want to see 8000 rpm though. I'm sure I'm a little unclear. I'm Mr. Mom today. I get the kids set up with an activity and here they come halfway through a post completely blowing apart my thought process lol.