Features Made of high quality T-304 stainless steel with computerized mandrel bends for strength and durability i.e. Maximizing smoothest high exhaust air flow rate TIG welded CNC machine flange 2-Piece 4-1 Racing design(8-2-1) Increase high flow air, instantly gain 10 to 15 Hp. / Tq. Engineered and Tested to Exceed Original Equipment Standards and Performance Fitment Fits Chevy small block 265-400 V8 engine Fits 1935-1948 fat fender well street rod and pickup application Fits most angle plug heads