OER Parts offers a wide selection of Oil System & Parts for your 1978 GMC C15 Suburban. OER Parts offers 1978 GMC C15 Suburban Bypass Valves, 1978 GMC C15 Suburban Dipsticks and Tubes, 1978 GMC C15 Suburban Filter Adapters, 1978 GMC C15 Suburban Oil Coolers, 1978 GMC C15 Suburban Oil Filters, 1978 GMC C15 Suburban Oil Pan Baffles, 1978 GMC C15 Suburban Oil Pans, 1978 GMC C15 Suburban Oil Pickup Tubes, 1978 GMC C15 Suburban Oil Pumps, and 1978 GMC C15 Suburban Oil Senders.