I am looking at 20'' wheels with 4.5'' backspacing for my 06 SCab Fx4. Are these the size I would need for the 8'' Rize? I am wanting 37's and maybe 38's but dont want any rubbing.

 

I responded to your other thread but I'll help out some more. I've got 20x10s with 4.5" backspacing on 37x13.50s, they'll rub the front valance a little but a little trimming and it'll be fine. If you do any offroading, you might need to trim in the rear of the fender liner and fender flare, if you've got them. I'm running adjustable Bilstein 5100s up front for an additional 2" of lift on my Rize 8" kit. I'm just debating on what to go with for the rear. But if you want the 38s than go with the spacer/leveling kit and bigger add-a-leaf or new leaf pack in the rear.