[Bigpapa@murph]

I'm messing with the same issue. 1992 gmc 3500 7.4l. This engine is rebuilt bored 30 over stock cam it is running 229 degrees. Cant get it down. New water pump new fan clutch new radiator the water wont return into the expansion tank. I reset timing to factory setting after unplugging set timing wire. I pulled intake and heads gaskets looked good was running lean and found vacuum line going to egr valve broken. I'm about to pull my hair out with this thing.