I have a 82 chevy BB 454. It runs well but it has a crack in the block. What is the best thing to do to fix this problem except buying a whole new engine?

 

where is it cracked.

used 454 block couldnt cost that much.
lots of chevy trucks used them.

 

They are getting pretty expensive in general, about 5 bills.

If the crack is on the outside in a non stressed area (not near the mounts or bellhousing), you can epoxy it. I have seen this used to cure external water leaks.

If its inside in the valley, mains or deck surface, its probably toast.