Starting in 1934 an add-on fan shroud was offered for larger trucks used as delivery and freight haulers. The 1937-38 trucks had a new part number for the shroud. It was available for delivery vehicles involved in stop and go driving, heavy hauling, and school bus applications. (In today’s world they slow over heating in slow moving parades.) The shroud was cataloged for ¾ ton, 1 ton, 1 ½ ton, and school bus vehicles for 1937-38.
Several part numbers are shown in the parts book from 1934-1942. The radiators were apparently the same width, however the larger trucks had a thicker core measuring three inches. The shrouds measure 18 inches wide by 7 inches vertical, and fit at the top of the radiator core.
I purchased a shroud that was an NOS item and installed it onto my 1938 ½ ton pickup. I was changing the hoses and coolant at the time so it made the installation of the shroud a bit easier. The top radiator hose should be off before installation, or risk damage to the radiator core or the paint on the shroud (I covered the radiator core with a piece of cardboard first). I brought the shroud in from the right side of the engine bay, working it into place. There is a mounting tab on each side of the radiator surround framework with pre-drilled holes in place. The mounting holes are right at 18 inches center to center; two screws with washers and nuts were used to hold the shroud in place. Once again, the shroud extends downward approximately 7 inches from the top of the radiator core. It is an add-on accessory that helps the fan to better pull air through the radiator thus keeping the engine cool.
Radiator Hose Specifications, (1938):
Top hose, Thermostat housing to radiator: 1 1/4” ID X 6 3/4” length
Bottom hose assembly, Water pump to metal elbow: 1 1/2” ID X 2 3/4” length
Metal elbow to lower radiator fitting: 1/2” ID X 5” length
Use all new clamps
Fan to radiator clearance: 9/16” minimum
Sources:
Chevrolet Master Parts Price List 1929-1942
GM Heritage Website
Personal experience
Article written by Glen Andrews, North Carolina
