How long til I ditch the inner fenders?

[muddpile]

Well, it's been 7000 miles and the 15's are finally shot on Fast Orange. The truck has a 3.5"/5.5" drop with 255/70/15's on factory 80's truck rallye's, 29" total height. The tires rub on the outside edge of the inner fenders right now, so for sure I need more backspacing.

Here's the dilemma: I want to go lower, 2" on each end. That puts me at a 5.5" front (3" spring, 2 1/2" spindle) and 7.5" rear (5.5" leaf flip, 2" shackle). I will also be purchasing 20's. Coys C5's to be exact, 20x 8.5" all around with 5.25" backspace and 255/35/20 (27" tall tire).

I have stock inner fenders on the front, and will be keeping them. Will this all work out, or should I consider not going as low? I notice Coys also make a 20x7, but narrow 20's are hard to come by.