Big Block, Chevy, Merlin Marine Engines. This Active Thunder was highly engineered with a single, step hull to be faster than any other boat in its class or smaller. She is a 3X Offshore Champion. Engine info according to the Seller: Engines have only been run on the dyno at this point. No hours on the engines yet. Interior is finished. New engines just installed. The seller installed 750 Hp 572 cubic inch, engines built from Chevy Blocks. The gear ratio on the #6 Drives are1:5. Engines have a flush kit installed on the motors so she can be flushed on a lift, or trailer...