This is a set of Stock stroke 3.400 JE Pistons for a 1986 or 1987 Buick Grand National, T Type, Turbo T, or GNX 3.8 liter turbo V6. The overwhelming choice of the world’s fastest Buick engine builders. These pistons are engineered to produce maximum horsepower in extreme boost or nitrous applications. The inverted dome is designed to duplicate the factory compression ratio and the precision CNC machined ring grooves accept 1/16, 1/16, 3/16 rings. Kit includes 6 Pistons (bore of your choice), .940 pins wth double spiro locks, and rings! Please specify what bore you would like upon purchasing.