OER Parts offers a wide selection of Body Panels for your 1976 GMC All Models. OER Parts offers 1976 GMC All Models Full Firewall, 1976 GMC All Models Partial Firewall 1976 GMC All Models Firewall Body Mount Patch Panels, 1976 GMC All Models Firewall To Floor Braces, 1976 GMC All Models Firewall Extension, and 1976 GMC All Models Firewall Delete Plate.