Alright. I decided on the Auto Spring 2.5" leveling kit on my '05 SCAB 4x4. Now on to the wheels and tires. I think I am set on this:

HELO Big Dog 17x8 w/either BFG AT-KO 315/70-17 or Terra Grapplers in the same size.

How far would these stick out?
Any potential problems or other mods necessary?
Is there a noticeable difference between the 305 and 315?
Lastly, the cost difference between the 17x8 and the 17x10 rims is only $10.00. Which direction should I go?

 

How far they stick out depends on the wheels backspacing. Do you know how much backspacing the Helos have? As for tire sizes, the first number is the width of the thread in millimeters. So a 315 will be 10mm wider than a 305. Also, as a general rule, with a 2.5 inch leveling kit on a 4x4, you can fit 35 inch tires with the OEM wheels or 33 inch tires with aftermarket wheels. The 315/70-17 works out to be a 35x12.50-17 tire. To complicate matters farther, Ford changed brake calipers sometime during the 05 model year which is causing fitment problems with some, but not all, aftermarket 17 inch wheels on newer F-150's.