By 1958 the Chevrolet V-8 fan shroud (not GMC) changed to the more traditional round design. During the V-8 beginning years in 1955-1957, it was little more than four pieces of custom sheet metal that helped pull air through the radiator core.
The enclosed pictures are of an original fan shroud for a 1958-59 Chevrolet 283 V-8. It fits only these two years of light trucks. Dimensions of the barrel is 19 inches in diameter and 20 inches deep.
The other shroud is from a 1958-1959 1 1/2 and 2 ton with V-8. There is a big difference. Be sure you purchase the correct design for the truck you have.
1958-1959 Pick Up (above)
1958-1959 1 1/2 – 2 Ton (above)