Titan Self Sealing Copper Head Gaskets; fits Buick 231ci ~ 3.8L V6. Gasket Thickness: .072″; Note: *Special Order Thickness* Bore Opening: 4.010″. Material: Copper with built in coolant and oil seals. These gaskets can be used on both Stage 1 (8 Bolt) and Stage 2 (14 Bolt) Buick V6 engines. Package Contents: 1 Pair.