Precision laser cut from 3/8" thick 304 stainless, our header flanges are manufactured in the U.S.A. and are machine surfaced. These header flanges are specifically made for the Audi RS6 4.2L engine. Port Size: 1.630"
We carry over 250 different header flange designs, so if you don't see the flange you're looking for, talk with one of our tech reps about custom header flange cutting.