First off, thanks for the help about tire size. I am new here, but from the posts, you seem to be the man, with the answers. I have found the $ for rims, and want to purchase Helo Maxx6 rims, 17 x 8. I want to run Terra Grapplers, 295/70/17, on them. From what I have read, they are pretty close to 33 x 12.50. I have a 2006 F-150 4x4 with a 2.5" A.S. leveler Kit, what back spacing would I need, to assure clearance.

 

295's are closer to, if not 34" tall, but they should fit on your truck fine with the 2.5" AS, can't help you much on the backspacing though, I'd guess around 4.5"

 

Right, the 295/70-17's are basically a 34x12.00 tire. I'd stay close to the OEM backspacing, which is 5.5 inches. Just be sure to test fit a wheel first. There have been some clearance problems with a few aftermarket 17 inch wheels on late production 2005 and newer trucks.

 

I'm running 17x8's with 5.5" BS and clear 315's. I had 17x9's with 5" BS on before with 285's and they had a lot of room. The 295's ought to look great on your truck, and like Wandell said test the 17" wheels to make sure they clear your brakes.