Others may vary, but I just tried matching to the most common, original fasteners on the truck. The main body bolts are nice because the washers on them have tiny bumps that dig into the metal just like some of the original grooved ones (A & B).

A) Hex Head Body Bolt, black oxide 5/16-18 x 1 Auveco 9756
B) Hex Head Body Bolt, black oxide 5/16-18 x 1-1/4 Auveco 8847
C) Hex Head Body Bolt, black oxide 5/16-18 x 3/4 Auveco 10084
D) Hex Head Body Bolt, zinc 5/16-18 x 1-1/16 Auveco 17035
E) Extruded U-Nuts, black oxide, 9/16 hole center to edge 5/16-18 Auveco 10053/12265
F) Free Spinning Washer Nuts, black oxide, 1/2 Hex Head 5/16-18 Auveco 15350

