OER Parts offers a wide selection of Automatic Trans & Components for your 1978 GMC C25 Suburban. OER Parts offers 1978 GMC C25 Suburban Complete Transmission, 1978 GMC C25 Suburban Cooler Lines, 1978 GMC C25 Suburban Dipsticks & Tubes, 1978 GMC C25 Suburban Flex Plate, 1978 GMC C25 Suburban Gaskets, Seals, Filters & Hardware 1978 GMC C25 Suburban Modulator Valves, 1978 GMC C25 Suburban Shift Knobs, 1978 GMC C25 Suburban Shift Linkage, 1978 GMC C25 Suburban Shifters - OE, 1978 GMC C25 Suburban Shifters - Performance, 1978 GMC C25 Suburban Torque Converter & Covers, 1978 GMC C25 Suburban Transmission Pans, and 1978 GMC C25 Suburban Vacuum Lines.