You would not be able to fit a 295/65R20 (35"x11.61") tire with the Fox coilovers, at least not without trimming and removing your crash bars. The largest tire we generally recommend with this kit without trimming/crash bar removal is a 295/55R20, which is a 32.8" x 11.61" tire. You also state that you want to use a 3" rear block with this kit, but the Fox coilovers 2" of leveling ability will still leave you with some front rake. Adding a 3" block will give your truck quite a bit of rake, which will be far from a leveled stance. If anything, a 2.5" from leveling system of some sort is generally all that's needed for a dead-level look.