1. The GMC engine is about 1.5" longer, all towards the radiator. There was a brand new Chevy radiator in my '52 GMC when I bought it. There was not enough room to get the fan belt on or off without removing the radiator. Being cheap, I removed the radiator, took it to a radiator shop and had the flanges on the sides redone to move the core forward.
2. GMC radiator fill spouts come horizontally off the top tank, then curve up. A Chevy radiator has the filler on the top, which ends up being inaccessible under the top of the radiator support (6.0450 below). While I had the radiator flanges being modified, I had the radiator shop remove the top fill and put a 90 degree filler on the engine side of the top tank as shown in the picture below.
Any modern replacement for a GMC radiator will use a pressure cap on the fill spout, not a separate pressure valve as shown just to the left of the top radiator hose connection in the picture below.
Last edited by Bill Hanlon; 01/21/20245:57 AM.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
