OER Parts offers a wide selection of Cooling System Components for your 1981 Pontiac Firebird. OER Parts offers 1981 Pontiac Firebird Overflow System Components, 1981 Pontiac Firebird Bottles and Caps, 1981 Pontiac Firebird OE Style Radiator Overflow Jars, 1981 Pontiac Firebird Stainless Steel Radiator Overflow Tank , 1981 Pontiac Firebird Overflow Jar Bracket, 1981 Pontiac Firebird OE Style Overflow Jar Cap, 1981 Pontiac Firebird Billet Aluminum Overflow Jar Cap, and 1981 Pontiac Firebird Radiator Overflow Bottle, Hose & Cap Set.