Since you're getting a really nice prerunner type of pkg, you might consider going with a lighter wheel and tire combination. 81 lbs. tires, and
? lbs. big, heavy rims will have an affect.
Also, with a 10" wide wheel you will need to do some major trimming at the pinch weld. The bracket lifts move the wheels forward by about an inch, but I don't know if the 4" spindle does.
Also with a 4" spindle, stock backspacing. and 13.9" wide tires, I think you will rub the spindle. If you are set on 20s at least go for this PC X AT, 501235 35X12.50R20 34.6x12.5 and 71 lbs. Might not work either ... but you'll have a better chance.
*I've read that the size of the 20s' opening helps to clear the spindle due to it's shape, Idk, but I'd consider smaller Thugs.
Thug 3991-8938A 18x9 0mm 5" b.s. 6-5 1/2, (*these mightl give you an extra 1/2" of spindle clearance, plus the tires about another 1/2" of extra clearance), PC X AT 581235 35X12.50R18 34.8x12.8 at 68.9 lbs.
This tire/wheel will also require less cutting at the pinch weld.
Thug 3991-78538 17x8.5 -6mm 4-1/2" b.s. 6-5 1/2, (*these might give you an extra 1" of spindle clearance, plus the tires about another 1/2"), PC X AT 57035 35X12.50R17 34.9x12.9 at 66 lbs. This tire/wheel will also require less cutting at the pinch weld. [This size might require mild caliper grinding. and will not work with '08s or the Stillen Big Brake kit].