Just did an extension of a 1972-1978 Z50 swingarm for a bike I am building. Turned some 40mm slugs.The slugs and cut ends of the swinger were beveled a little nicer than this for the final welding, but you get the idea. Bevel it out good and you will not need to grind too much of your weld.This is an adjustable jig for swingarm extensions. It is very helpful to keep everything aligned.The brake arm after getting extended with a couple more headed for zinc plate.The finished swinger next to a stock one. Everything is bead blasted and headed for powder coat.There are a couple 72-78 softails going together here. One will be a fairly stock 72, and the other a 73 custom.The stock chain guard will be used, so the rear mount had to be moved forward. The old mounting tab was filled and ground smooth.