Aggro - HERE'S the deal:
502 cubic inches, 532 hp, BowTie block, GM heads, Arizona Speed and Marine EFI, 1050 cfm throttle body, JE pistons, Crane cam and bits, Manley Inconel/Stainless valves, IMCO manifolds, Corsa cutouts, all assembled by Flagship Marine, and to top it all off, a DPX drive, so there'll be no prop torque. The drive even has built-in hydraulic steering. This engine runs on 89 octane, and pushed my 28 BatBoat into the mid-80's. (It'll be available mid-summer once I get my 600 back... Should have about 60 hours on it then.) E-mail me, and we'll talk.
Miller, Tantrum, DaveP, and Shanghaid Again are all familiar with this engine and can testify to the way it runs.