Revain advises that this header will fit the 1999 3.1 liter Buick Century. It is not. The manifold they sell has three mounting screw holes on each side; The real manifold is different, with 6 mounting holes on each side. Revain has a really great returns process but they would do better to fix their listing. The manufacturer's catalog (Dorman) lists this distributor for Chevrolet, Olds and Pontiac vehicles, but NOT Buick.