Lifting a tire has to do with poor suspension geometry, control arms are prolly too steep. He was prolly getting a little flame flex before and not lifting a tire, now no frame flex and it lifts a tire. Also easily done with no rear
swaybar.
I'd use bushings on the frame tie-ins, it's the proper way to do it, otherwise you're making all 11 body bushings useless and transferring all chassis vibes into the body and passengers. easier on parts also.