It's not the positioning of the panhard. Perfectly centered. When I raised the rear-end to ride height, the upper control arm slipped right into place without having to be moved at all. And measuring everywhere I could also indicated the rear-end is perfectly centered at ride height.
So, I'm still pretty stumped. Trying to decide whether to take out the axle and put in the rubber bushings. Shouldn't hurt. It's just an awful lot of work for something that may or may not fix the problem. On the other hand, if I decide to go with different lower control arms with the spherical bushings, the rubber upper bushings would probably still be a good idea.
Another interesting discovery. I may be testing this all wrong. With the suspension completely unloaded, both sides were showing the same distance to the rim that I was getting before with just one side raised.
Which proves that when the right side comes off the ground with the lift, it's not bind that's raising it. It's the shock reaching its travel limit.
I suppose a more correct approach would be to lift the right side only until a certain amount of weight is on the right rear tire. Like 500 lbs. On the track, I'm sure it's not a matter of the rear tire coming off the ground. It's just getting too little weight on it.
You don't suppose the presence of the panhard could be an issue, do you? With such stout bushings, the panhard certain isn't needed anyway.
Know if Pete's around this weekend? Could you check with him and see if he minds if I call with some Mustang-specific questions and PM me the number if he's alright with that?
For now, I'm going to remove a panhard end-bolt and re-test height differences even though I'm convinced my method is flawed now.
Edit: Reading up on panhards right now. At first glance, I'm not sure if the panhard is helping the control arms bind in the turns by forcing the rear-end to the side when a side of the car is raised, or if it's preventing bind by limiting how much lateral motion occurs.
