OER Parts offers a wide selection of Valve Covers for your 1978 GMC Truck. OER Parts offers 1978 GMC Truck Aluminum Valve Covers, 1978 GMC Truck Chrome Valve Cover, 1978 GMC Truck Transparent Valve Covers, 1978 GMC Truck Logo Valve Cover, 1978 GMC Truck Finned Valve Covers, 1978 GMC Truck OE Valve Covers, 1978 GMC Truck Billet Aluminum Valve Covers, 1978 GMC Truck Low Profile Valve Covers, and 1978 GMC Truck Tall Profile Valve Covers.