OER Parts offers a wide selection of Body Panels for your 1958 GMC 300. OER Parts offers 1958 GMC 300 Truck Bed Components, 1958 GMC 300 Stepside Bed Sides - Full, 1958 GMC 300 Bed Sides - Partial, 1958 GMC 300 Running Boards, 1958 GMC 300 Side Steps, 1958 GMC 300 Patch Panels, 1958 GMC 300 Front Bed Panel, 1958 GMC 300 Stake Pocket Repair Panel, 1958 GMC 300 Bed Floor Panel, 1958 GMC 300 Stepside Rear Fender, 1958 GMC 300 Fiberglass Bed Side, and 1958 GMC 300 Rear Bed Corner.