I think you overfilled the radiator and that the truck's cooling system was just finding it's correct level.
When cold, the coolant should just barely cover the radiator tubes.
Is your cooling system a zero pressure system?
My truck had a coolant recovery reservoir on it when I got it. I like it because I can fill the radiator to the very top and coolant doesn't spill on the ground during normal operation.
The reservoir rises about two inches when hot, and goes back down as the engine cools off. The truck operates at a steady 180 and has a 4 lb pressure cap.
1950 Chevrolet 3100 (Ol' Roy)
1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)
