Stuck engine

[stevede]

I have an inboard V-8 engine model # 502SPHRCTR with an OMC stern drive.
When it was stored last winter the lines were drained and this spring the engine is stuck (won't turn over even with a lot of force). I was wondering what your suggestion for repair / replacement would be and what parts would be available.
Could this be corrosion although it was only on fresh water last year? It is a 1983 Model.

[boats.net]

You can try to free the motor up. Remove the spark plugs fill with some marvel mystery oil (or equivalent). Moisture in the motor or lower unit can cause the motor to sieze.