OER Parts offers a wide selection of Body Panels for your 1974 GMC C15/C1500 Pickup. OER Parts offers 1974 GMC C15/C1500 Pickup Full Firewall, 1974 GMC C15/C1500 Pickup Partial Firewall 1974 GMC C15/C1500 Pickup Firewall Body Mount Patch Panels, 1974 GMC C15/C1500 Pickup Firewall To Floor Braces, 1974 GMC C15/C1500 Pickup Firewall Extension, and 1974 GMC C15/C1500 Pickup Firewall Delete Plate.