The radiator is new as it went in with the engine rebuild. I've had the truck for 20 years. It has always had a 235 from the time I bought it, but the guy who took out the original 216 and put in a 235 used the regular sized (longer shaft) water pump which caused him to cant the radiator to make clearance for the cooling fan. The old block freeze cracked and I replaced it with a 235 out of a '61 Biscayne about 10 years ago when I was restoring the truck. When I did that, I bought a short shaft water pump from Jim Carter's. It has the larger diameter hole for the 216 flat back cooling fan since there isn't sufficient clearance to use a regular 235 cooling fan. The instructions were to use a 216 cooling fan with the water pump, but it overheats in no time and has ever since I restored it. As it is, I have about 1/2" of clearance between the radiator and the cooling fan, so there is no room to put in a 235 fan. Hence the idea of an electric fan in front of the radiator.

1953 Chevy 3600 3/4-Ton