I don't know about the GMC, but I do know the '60-'61 Chevy C10 had a fan shroud that looked like the passenger car shroud. The '62 had a beefier, more stoutly built fan shroud, but it still looked like a barrel stuck to the radiator.
'63-'66 also had a shroud; 3-piece style, with side skirts that removed.
I've seen both the '60-'61 style and the '62, and for my truck I prefer the '62, which should bolt into the earlier ones.
I would suspect the GMC versions are the same, since the core supports and all the front sheetmetal are the same.
-Brad
