You probably have heard this already, but if your truck has been sitting so long you can bet the the block needs a good thorough flushing. I have done this on a number of old motors, and finally I learned that if you haven't opened up the rear petcock on the block (down behind the steering shaft)you haven't really flushed it. When I have finally got that drain opened usually it is so gummed up down there that nothing will drain. I've had to go in with a chopped off clotheshanger to loosen the crud that accumulates back there. When it finally starts to drain it will be pure mud. Failure to flush this crap out can lead to overheating and a cracked block. Don't ask how I know this last part.

Karl

It may not be the easy way, but it is the Cowboy Way - Ranger Doug
Beware of the stories you read or tell; subtly, at night, beneath the waters of consciousness, they are altering your world. - Ben Okri
1953 Chevy 3100
1960 Volvo PV 544
1941 Chevrolet Special Deluxe