Xnke from HybridZ is making the header for me. I had the flange laser cut from stainless 304.

I made an adapter block that bolts on a stock head and positions the flange where it will be with the KN20 head.

Made a mandrel to form the stubs into an oval.

Really happy with the fit

Remember kids good fabrication is all about joinery. The better the fit the smaller the weld. The smaller the weld the less the warp.

This is nice to see.