This is a set of GN1Performance "KB-4 HEADERS" for a 1986 or 1987 Buick Grand National, T Type, Turbo T, or GNX 3.8 liter turbo V6.The difference between these and the regular "KB Headers" is a 4 bolt flange rather than a 3 bolt. They feature HUGE ports and are welded all the way around each tube! These headers are only available in none polished raw stainless finish. They are complete with gaskets, clamps, and cross pipe. *These are for competition use only modifications or adjustments maybe required.