How wide wheel spacers do I need in order to run 285/70/r17 Cooper STT's on my JK X stock height, without rubbing issues and no lift? (I will not be disconnecting sway bar for the time being, I am saving up on getting a bb lift)
a. 1.5'
b. 1.25'

or some other?

I am running on Rubicon 17' wheels

 

i have the spidertrax 1.25 wheel spacers and I am running stock wheels with 315/70/17's.. no rubbing what so ever.. got them from northridge 4x4

 

With a approx. 11.5" tire you should be okay with both it will depend on if you want the tires to stick out alittle further & have a wider stance I would go with the 1.5".

 

I liked the 1.5 but you should be fine with either.