Re: Oil in Coolant 302 efi
My unlcle had a 96 Fairmont 302, that did some weird things too, no matter what you did to it, it would alwyas overheat, countless recond radiators, water pumps, thermostats, they would all work for a short time then wammo, hot as hot and would over heat. I know it sounds irelevant however for some reason the odd late model injected windsors had really weird bugs. His also used oil, could never work out where it was going as it never blew smoke. These engines are plain weird.
If you have some kind of oil in your coolant and not in your sump (have you checked that) then its unlikely to be a water jacket crack. Check your auto trans fluid if that milky after it been running for a bit. Failing that, why not try a ten dollar bottle of stop leak. There is one with floating metal filings that I've had excellent first hand experience with.
If its none of those things all I can think of is a hose or pipe going somewhere it shouldn't???
My uncle is a Mechanic who specialised in Fords and Chryslers back in the early 70's, he often says that the best coolant and radiator inhibitor is some sort of oil. I can't remember what it was, something like neatesfort oil or something like that.
Hope some of this helps
Goodluck on finding your Gremlin.