OER Parts offers a wide selection of Heater Parts for your 1948 GMC All Models. OER Parts offers 1948 GMC All Models Expansion Valve, 1948 GMC All Models Hose Clamps, 1948 GMC All Models Hose Fittings, 1948 GMC All Models Hoses and Lines, 1948 GMC All Models Vent and Duct Parts.