What causes the rubbing, is it the overall height of the tire or the width? I currently have 30x9.50x15 BFG All Terrains with no problems but was thinking about 30x10.5 or 31x9.5 TSL Radials.My Blazer is 1995 LS with 2 inch shackles and t-bar crank of around 1.5 inches. I would be mounting the TSL's on factory steel spare wheels.

 

It's really a combination of the two, with that lift and stock width tires you should be fine. What happens is when you don't lift, and up the height of the tires, they cover more ground when turning left or right.

Same thing when you put wider tires on. That's why generally when you're lifting, and you want wider tires, you have to go for a bit less backspacing to avoid rubbing against sway arms and frame rails. Problem with when you decrease the backspacing the tires stick out further and you end up trimming the fenders since the tires now rub the fenders at full lock and suspension compression.

So with the 31's, I believe 9.5 is the stock spec width for our trucks, you shouldn't have a problem, you may have an issue with the 30x 10.5, but I think they'd clear with a lift, the fact they're 30's may look kind of funny though.

Here's an example of what I'm talking about, You can see how the Blue (30 inch tires) doesn't rub the black frame rail/sway bar/whatever. But as soon as you slap the 31's on (the red) you can see the extra little bit of height causes the rubbing. This is a top view. With 2 inches of lift, you miss the taller part of the tire so you won't have rubbing issues, if you do, it won't be too severe.

 

Thank you I will keep that all in mind when I am ready.