Thanks guys. Tester- I’ll check for bubbles in the coolant. George- yeah, the fan spins when it’s overheating and I thought the same thing about the radiator cap, so I replaced it- no joy.
Crap! As you can tell by my initial post, I suspected the head gasket. It’s a good car, but not worth paying for a head gasket. I guess I’ll just keep the trips short and keep doin my coolant pour back routine until she dies.