1995 Buick Riviera Engine: 3.8L V6;EngineVIN: 1; Molded Rubber; Water Pump Mounting Gasket;. 1995 Buick Riviera Engine: 3.8L V6;EngineVIN: K; Molded Rubber; Water Pump Mounting Gasket;. 1996 Buick Riviera Engine: 3.8L V6;EngineVIN: 1; Molded Rubber; Water Pump Mounting Gasket;.