I have a 255/50 17 on the front and a 275/50 17.. now logic tells us those are different both height and width. I have yet to experience any problems with my ABS and I also just put 2in spindles on the front and I am completing the drop tomorrow. Even with the front 2 in lower than the rear I still dont have ABS problems. So me being all for staggard fitment cuz it looks bomb ***, go for it, u wont regret it. Just like visciousknid said, make sure that the wider wheel on the rear has a greater offset to tuck it in the fender. Right now my rears stick out about a 1/4 in so I cant go much lower than the 4 in the rear

 

If your talking about different wheel size's you can do it on the 2wd but not the 4wd becasue it may cause a risk of breaking the transfer case.

 

good call. it'd be more risk for the transfer case tho wouldnt it?

 

I run 255/60/17 up front and 285/60/17 in back. There is about an inch and a half difference in the two. I have not had a problem yet.

 

Yep thats what I wanted to say. Fixed