I upgraded my power this winter on my 1994 Aggressor, went from a 365hp merc magnum 454 to a custom built 580hp 496. The 454 turned a 25P RH Mirage 3 blade to 64mph at 4600-4700 rpms.

Can you guys give me a good recommendation on a good prop for the new motor? I was thinking maybe a labbed 4 blade 28P might be the ticket

That sounds like a good prop to start with. cdaniel525 has a 500hp engine in his boat and runs a 26p 4 blade bravo.

Got any pics of that new engine? That should be mean, your cruise speed will probably be around 60mph now.