Hey folks, so I have a 1988 'burbon with the 5.7 fuel injected V8 and I love the thing to death but, I've been having some head gasket issues. I took it to a shop and they said the heads are warped and its going to be about 3,500 dollars to replace the gasket and get the heads machined or to swap them with fresh ones. So I have been thinking about getting the engine swapped I have a gear head buddy that will swap then engine for 1,200 (he won't just do the gaskets and heads). So I think for the price It might be cheaper to put a new Engine in. I was wondering if anyone could point me in the right direction of a good motor to put into it. I don't know if I should put a crate motor into it or try to find a good motor on a used car to drop into it and Honestly I don't know much about motors so what kind of motor should I put into it and what other cars could I pull an engine out of. I live at an elevation of 9,000 ft above sea level and it has been affecting my cars powers is there an engine that might be better geared for this?

Thank you for reading and I would really appreciate any help,
Alex