Got everything running and operational. Tested systems out of water with earmuffs and all was operational. Put the boat in the water and immediately lost the impeller (assuming) as the water temp continued to increase well above 200 as I headed back towards shore. After inspection, found rubber pieces in the inlet ports of the lower unit. Since I'll be disassembling the outdrive, I'm looking to identify it since it does not fit into any of the categories for common outdrives. I've researched enough to find 1963 is most likely one of the first Mercruiser I/O's. I've also tried to categorize as a Merc 1 with no matching housings. It's impossible to locate the parts I'll need without properly identifying this unit. Is anyone familiar with this unit? HELP...?