[Chuck78]

A guy on the GMC V6 email list told me that the panels used different bed mounting pads from the pickups. The mailorder parts place in Canada looks to have these in their stock for $50-something. The ones they show a photo of are the larger rectangular ones that I have it seems.

Another gentleman on the GMC list sent me a link to a photo of the underside of a 64-66? GMC (the later years that had leaf springs), and although it is not the X-frame, this picture pretty clearly shows no cross sills directly over the axle where the cross sill in question on mine is located. See attached picture, and note location of perimeter wheelwell bolts in bed wood vs the next rearmost cross sill.

I would be very satisfied to see this same view on an X-frame panel truck on a 60-62 (or was the X frame until 63?).