1987 cruiser yachts Holiday 25 w 260 Alpha sbc and raw water cooling. The engine is seized and i am looking fervently for a trailer. In the meantime can i break down the engine at all while sitting in water. Ill probably end up twisting in a plug but am hesitant to even take off the thermostat housing while she is in the water. Any advise on how far i can dig into the block while in the water will be appreciated.