OER Parts offers a wide selection of Oil System & Parts for your 1975 GMC C35. OER Parts offers 1975 GMC C35 Bypass Valves, 1975 GMC C35 Dipsticks and Tubes, 1975 GMC C35 Filter Adapters, 1975 GMC C35 Oil Coolers, 1975 GMC C35 Oil Filters, 1975 GMC C35 Oil Pan Baffles, 1975 GMC C35 Oil Pans, 1975 GMC C35 Oil Pickup Tubes, 1975 GMC C35 Oil Pumps, and 1975 GMC C35 Oil Senders.