Update: I peeled up my carpet on the driver's side and there is warm dampness on top of the tranny hump behind the radio. The leak appears to be before the heater core, perhaps right when the lines come into the cab, its not big but plenty annoying. Is there an easy way to get to the hoses/connections instead of the heater core, perhaps by pulling them out through the outside or something? Tomorrow I will look at it closer (time for work now) and see if I can find something else out. thanks.

It's hard to beat old trucks!!