Head gasket on GMC jimmy

You would need some service records to prove if the head gasket had ben replaced, otherwise one would not know. The best thing to do is to do a engine compression test and verify the cylinders compression. If there where a blown head gasket, cylinder compression would show low between some cylinders. There would be white smoke coming out the exhaust with a sweet smell, or the engine oil level would have coolant in it.

Engine- well I know it has one! But I'm afraid I can't tell you anymore. I did have a near blowup & replaced the manifold w/ both upper & lower intake gaskets, thermostat & serpentine belt. No more coolant leaks or overheating now. Thanks both of you.