I just bought a boat with a 1996 Crusader 5.7 GM 350. It has been sitting for 3 years. I took off starter and it had broken teeth. I replaced starter and it became jammed. After taking it off, I tried to turn engine over by prying flywheel with a screwdriver. It will turn in reverse, and when I try ccw again, it will turn to the same point, then get jammed. I don't want to force it and cause any damage if some has not already been done. Plugs are out, valve covers off, manifolds off. Where should I go from here?

 

Is the engine still connected to the outdrive?

 

Pulled engine out. Will strip down in next couple of days. Afraid it's a connecting rod.