Kenneth, 

The one piece of missing info is which engine
it has: An '83 could be diesel, aircooled gas,
or water cooled gas (wasserboxer). 

Since it was *gas* forced into the oil, I'll presume its not diesel. 

I think the aircooled is relatively easier and cheaper to rebuild than
the wasserboxer. 

If a transplant is what you are thinking, seems like an early
wasserboxer would be a good candidate for a Subaru engine, if that is
your inclination. 

Good luck,

Tom F.