I'm not sure on your 1960 GMC, but on older GM trucks, they mount behind the front bumper, to protect the grill from stone chips, etc. There would be only one, unless the "later" pans come in two pieces. The shield also makes a nice step to stand on when checking oil. That is, for those who aren't tall enough to reach over the fender.
They should have some attached brackets for attaching the pan to the bumper brackets. I don't remember them attaching to the frame in front of the grille, but maybe they attach there as well. Mounting brackets on the pan should indicate where they might attach.
Harvester
