I have found a 99 XJ with what the owner says has a blown head gasket. I have changed my share of engines but not a Jeep. What kind of money do you get into with swapping a engine in one of these? If I am going to change out a engine it will need to be a good one. I don't like doing things like this twice. Where do you find a good engine?

They're quite easy to swap.

Junkyard?

What is ballpark price for a 4.0 in a junkyard

Call around. It varies by location.

I get $500 for one that a guy can see and hear run.

Thanks, I don't think I can trust just replacing the gasket\head on one I know nothing about