[Rick Norwood]

You are not dealing with paper thin gaskets. both the intake and head gaskets are thick gaskets and more than likely eaten away by the flush/Dexcool. so It would be worth your while to tear the intake manifold and/or the heads off and inspect. But before you even go that far, you might try getting a radiator pressure tester and pump up the cooling system and see if anything leaks around the Intake manifold. You won't see an internal leak this way, but I seriously think a quick teardown might just reveal the smoking gun. My 2001 S10 intake manifold gaskets literly come out in small pieces as well as eating holes into the intake manifold itself.

I have not had good luck with either used or rebuilt engines. You will be a lot better off fixing your own engine if the gaskets are the culprit.