Header Flanges galore

As a person who has been Bending exhaust for 20 years plus, trying to find exhaust header flanges is sometimes as a real pain because sometimes nobody makes them. So what I've done is I've started to make 3/8" thick header flanges with matching graphite gaskets that are about half the cost of Flanders that are out there online without the gaskets

[@GT140T]

How thick are your flanges. 460 Ford.