I found these 3/8" thick header flanges at Advance Adapters for $45.00 for the pair plus shipping. They are the nicest flanges I have ever bought. Now to make the round pegs fit the square holes. I'm going to make another set of Kenne Bell type 3 into 1 headers for the truck like I made years ago, but with a few changes in the collector. I will use 16 gauge mild steel. I could use stainless like I did for my cutouts and exhaust system, but welding small 1 5/8" stainless tubes causes a lot of sugaring inside the tube unless you seal them and flood the tubes with argone while welding. I used a flux on the stainless exhaust system to cut down on sugaring, but those pipes are big so it does not cause much restriction..