OER Parts offers a wide selection of Cooling System Components for your 1985 GMC C2500. OER Parts offers 1985 GMC C2500 Overflow System Components, 1985 GMC C2500 Bottles and Caps, 1985 GMC C2500 OE Style Radiator Overflow Jars, 1985 GMC C2500 Stainless Steel Radiator Overflow Tank , 1985 GMC C2500 Overflow Jar Bracket, 1985 GMC C2500 OE Style Overflow Jar Cap, 1985 GMC C2500 Billet Aluminum Overflow Jar Cap, and 1985 GMC C2500 Radiator Overflow Bottle, Hose & Cap Set.