Jim, dump everything. Start from scratch. Flush cooling system, change oil and filter, drain and change ATF and filter. Cheap insurance. There is no telling what happened to that motor when the head gasket was replaced. Better to be safe than sorry (why didn't I think of that )...

__________________
Jeff Lawrence
1989 300e
2000 Dodge Grand Caravan SE
No matter what you fix, there will always be something else to fix..
"Warranty" is just another way of postponing the inevitable.