Well I custom cut my headers and have them welded by a weld shop of less then 10.00
I have a .21 in mine was a miss bud now the Oberto. I'd watched how Orange county choppers does there headers, But I'd cut the pieces and tack then with super glue to see how eack pieces fit,then mark them so the welder can tac them before full well. if you deside to go that route that you boat with you with motor mounted and chech and see after each weld that still fits to your boat. I've done this six times on different boats headers.[8D]