For 66-87 Chevy/GMC SBC Truck Long Tube Black Coated Exhaust Headers This is a set of brand new small block Chevy black coated headers Fits for 1966-1987 2wd and 4wd Chevy trucks with Small Block Chevy The diameter of heavy duty tube is 1 1/2" The thickness of flanges is 5/16" Comes with the left and right headers, all gaskets, bolts, and collectors with flanges