View Here : 1987 Grand National Gnx
The GNX was introduced in 1987 as a limited-edition, higher-performance edition of the Buick Grand National. Buick produced 547 GNX models in 1987, a small number compared to the 20,193 Grand Nationals produced that same year.
This is a "Camshaft Button" for a 1986 or 1987 Buick Grand National, T Type, Turbo T, or GNX 3.8 liter turbo V6. This is highly recommended to change out on every camshaft, this is a needle bearing button where as the factory button is a plastic piece.