For what it's worth, I have a 66 C-20 with a 292 that doesn't seem to get warm in the winter up here (South Dakota) but is great during the summer. I put a piece of cardboard in front of the radiator when it gets really cold and it works like champ.

1964 Chevrolet C-20 Fleetside, Otis
1950 Chevy 1/2-Ton, Kirby
1950 Chevy 1/2-Ton Shortbed, Walter