This is a GN1Performance "3.5 INCH EXTERNAL WASTEGATE DOWN PIPE WITH A 46mm WASTEGATE" for a 1986 or 1987 Buick Grand National, T Type, Turbo T, or GNX 3.8 liter turbo V6.This is our all new 3.5" Inch External wastegate Downpipe constructed out of 304 stainless steel. It comes complete with a brand new 46mm wastegate, bolts, and gaskets. All tig welds and is built to clear headers. Requires a 3.5" Exhaust Cut Out, see related items to the right *Note-This pipe is also available with an 02 bung, please state if needed when purchasing.