mercedes 500SL 1991 need new engine

I''m the owner of a 500 SL 1991 and the car need a new engine.

Do the engine from a 1993- fits?
what about the engine from the w140 s500 1991?

Thanks, michael

If you can get a rebuilt, otherwise you''ll probably be buying more problems.  are you sure your engine is shot?  what''s the problem or problems and mileage.