I have a 63 C20 with a 292, the rear axle is 4.10, Monojet carb leaned out, 10 degrees advance on an HEI, cabover, and 33 inch tires in the rear. I flushed the radiator with the Dupont 2 part flush. Keep it filled with 50/50 anti-freeze, and a shot of rust inhibitor and water pump lube. If I push the engine to 3300 RPM and hold it for 20-30 minutes, I'll start to see the temp gauge start to move above normal. It's never over heated on me, except once when the thermostat stuck.

LG

I don't own a vehicle that isn't old enough to drink.