One thing here is that our cars are not all symetrically/centered put together b/c GM back in the days they were made pretty much though a 1/2"+/- was fine!!!
You can tell if your car's running gear is close to symetrical/centered to the body by sticking a couple of fingers between the tops of all four tires and "feeling" for clearance....
I bet you will find out that your car can take say only one "finger" on the drivers side and only a tight two on the pass. side. Thats how mine is, (or is it the other way around??), and I don't think it has ever been major tweeked other then a mild side-swipe/ditching on the pass. side at the horizonal door crease/bulge when I didn't have it.
All this throws a monkey wrench in setting up max. sized tire/wheel combinations on our cars...
And I went so far as, (again), "fingered" my cars subframe alignment holes to make sure my S/F was where it is supposed to be AND it is spot-on!!
I found out about the 1/2" +/- thing b/c my car had a settled coil on it early on AND I had to get the Factory Rep. to finally authorize a new set of h/d coils for my car that I got for their price, (something like $22/pr
.?? back then), and they put them in for free!!
The Rep. said after I told him it bugged me to no end that my dash was leaning towards the pass. side about a 1/2" and he said heck, thats the way they make them, tolerances are fine!! I said no way AND got my new BB A/C coils!!!!