This is a GN1Performance "3 INCH 46mm EXTERNAL WASTEGATE DOWN PIPE " for a 1986 or 1987 Buick Grand National, T Type, Turbo T, or GNX 3.8 liter turbo V6. This 3" Inch External Wastegate Down Pipe is constructed out of 304 stainless steel and comes with a 46mm custom wastegate. All tig welds and is built to clear headers. Requires a 3" Exhaust Cut Out or 3" Test Pipe, see related items to the right *Note-This pipe is also available with an 02 bung, please state if needed when purchasing.