southbenz

I just recently bought a 04' american offshore from a friend. It had a 500 efi with a vortec J trim supercharger. It now has a carburated 572 with the same supercharger. Im running a 30 pitch bravo prop. Im trying to figure out why it takes forever to plane out. It seems as if the prop is bitting too much but once the boat starts to break over it runs perfect. any help would be greatly appreciated. Im also planning on puting the efi from the 500 back on the 572 any thoughts on this?