IRS alignment setting for wide rear tires

[AIRSICK]

Thanks for the info on the spring plates. I thought that because the slots in the spring plates are elongated horizontally already for toe adjustment that I could elongate the holes in the TA vertically and that way I would have adjustment both up and down and front to rear without over sizing the spring plate holes.

But I still need to know if I use the middle bolt for the rotation center or the forward one closest to the torsion housing.