I helped a friend do this to his ramcharger, when we lined everything up, the front perch had to be relocated forward quite a few inches and the final spot made the wheelbase an inch shorter than stock due to interference with a body bolt bracket on the frame. He did shorten the driveline 1 inch. Assuming your doing a shackle flip, the pinion angle changed and points directly at the rear yoke on the tc. Since his spring perches on the axle were collapsed, we replaced those as well and lined up the pinion where we wanted it. Btw, the springs were near flat (64") when all the weight of the vehicle was on them, changing where the rear shackle needed to be mounted.