This is the early stages of a custom exhaust. I wanted something that would match the "D" shaped port to allow for better exhaust flow. I ended up TIGing together a 1" round and a 1" square tube to form the "D" and mating the stub to a laser cut flange made from 3/16" P&O. It'll eventually flow back into a round tube, possibly two staged, once I figure out my final shape.
