I won't ever say don't do it if you've good a pair of disks with life left in them and most of the bracketry. Don't want to get in to the ebrake, use a driveshaft brake? I feel convinced that the sticking issue that I was chasing is the one shoe chipping and the chip getting stuck - then ripping other one off. Was better while testing. While tweaking the speedometer drive gear in the evil one, I noticed the gear I installed in the survivor years ago when changing tire profile. Same gear. Checked the evil one, it has a 2.71 SG, so they match even more now. Explains why the clean one was always a bit crisper. 3.21 would kill top end and already have one of those so these are staying.