Overheating in 87 22RE.....

After about 3000 troublefree miles the 22RE in my Adventure, at 104,00 miles is
starting to overheat in a most pecular manner. Here's whats happened:

Two weeks ago I replaced a pressure cap that seemed to be releasing early. That
same day I had two overheats that were eventually traced to a pin hole in the
lower radiator hose. Replaced the hose and drove home, 125 freeway miles
without problem.

Yesterday I drove about 15 miles in town, no problem and then 30 freeway miles
before the temp started rising. I stopped and it was hot, blew out most of the
water when I released the cap.

I replaced the thermostat and let it run for over an hour without hardly getting
warm. I then drove about 15 intown miles, everything still OK. Drove home last
night on the freeway again and as I arrived at the house it was starting to get
hot again.

Allowed it to cool overnight. This morning I find that the radiator is still
full.

My thoughts, blown head gasket. Other suggestions are apprecaited.

Sunrader Bob
Riverside, CA