Accu Seal Pro Intake Gaskets for Dart/Buick Heads on SBC. The Dart/Buick SBC cylinder head was designed for the Buick NASCAR teams & borrowed its port & chamber configuration from the very powerful Buick Stage 2 Indy V6. Intake, Exhaust & Valve Cover are unique to this head. Compare to Fel Pro 1259. Material: Premium Composite; Gasket Thickness: .062″, Port Size: Trim to fit thru 1.600″ x 2.900″; Package Contents: 1 Pair.