Instead of cutting the frame, you could torch or drill the rivets out of the rear spring hangers, move the rear end forward, then drill holes for the hangers and bolt them in place. Thats what I did with mine.


'66 C60 body, '97 C6500 chassis, '07 LBZ Duramax with Allison 1000
https://photos.app.goo.gl/cxwv1C6Ay2oxYH7u7