OER Parts offers a wide selection of Oil System & Parts for your 1974 GMC Truck. OER Parts offers 1974 GMC Truck Bypass Valves, 1974 GMC Truck Dipsticks and Tubes, 1974 GMC Truck Filter Adapters, 1974 GMC Truck Oil Coolers, 1974 GMC Truck Oil Filters, 1974 GMC Truck Oil Pan Baffles, 1974 GMC Truck Oil Pans, 1974 GMC Truck Oil Pickup Tubes, 1974 GMC Truck Oil Pumps, and 1974 GMC Truck Oil Senders.