1970bbs Mercruiser 302 Ford Engine ceased

I inherited a boat from my Dad

I inherited a boat from my Dad. It had been sitting for several years due to a farming accident he had and was not winterized. It had been recently rebuilt before the neglect and only had about 25 hours on the engine. The problem appears to be that it is ceased up. I know that one soft plug is blown out but it doesn't appear to have any block damage though. Just wondering if anybody knows any trick on breaking an engine free. I heard from one person that I could try filling the entire engine up with Kerosene letting it set for a while and then try to turn the crankshaft with a breaker bar. Any suggestions short of pulling the engine out and tearing it down.

Try some WD-40 sprayed into ea

Try some WD-40 sprayed into each cylinder and let sit over night.

If there is a freeze plug out

If there is a freeze plug out you should pull the intake and inspect the water jacket under the intake before you spend alot of time trying to free the engine.
Most of the time the block is broken if it was frozen enough to push out a freeze plug.
The water jacket is not very thick in some places under the intake.