OER Parts offers a wide selection of Body Panels for your 1978 GMC K15 Suburban. OER Parts offers 1978 GMC K15 Suburban Full Firewall, 1978 GMC K15 Suburban Partial Firewall 1978 GMC K15 Suburban Firewall Body Mount Patch Panels, 1978 GMC K15 Suburban Firewall To Floor Braces, 1978 GMC K15 Suburban Firewall Extension, and 1978 GMC K15 Suburban Firewall Delete Plate.