This was a complete overhaul of a 2007 8.1 Horizon Mercruiser our of a 30' Sportcraft. The engine detionated #1 piston. Since the engine was already a reman engine and .060 over we subsituted one of our shortblocks as a core to rebuild since the crankshaft and cylinder bores were still standard. We completely rebuilt this from top to bottom including raw water pump, oil cooler, il lines, fuel injectors, etc.