Have a real nice boat. Caliber 1 206 Magnum. Has open bow. Anyway. Has a 350 mag and Alpha 1 Gen 2 drive. Only 440 hrs. Motor never apart and drive only for service and impeller changes. Motor runs perfect. Does not burn oil, leak anything and runs strong. I WANT MORE POWER. Do I build a nice small block and keep Alpha or go BBC and a Bravo? Now by answering this question it will create at least a dozen more. I am thinking 450-500 H-P. To get that out of a SBC I think I will be turning to many RPM's. Can get it out of a BBC at 5000 RPM no problem with a mild motor. What way do I go????