The SS body mounts made a difference to the point of I can't remember the last time I have heard the body hit the bumper. Well worth it for me.
When moderate wheeling here in MO I have yet to have the tire hit anything on a depart. Bottom of bumper, yes, a little, but not tire.
I just went out and measured. In my case the bottom of the spare is 32" from the ground (so a little less aired down) and 22" beyond the bumper plate.
Most of the time on vacation there's a hitch bike rack on my truck, the base of which sits below the tire by several inches. When the extension is in the lower position (sits a couple of inches below the bumper) it hits steps somewhat often, if they're tall enough. When it's flipped to the higher position it rarely hits during moderate wheeling- again below the tire. If I get a chance to do Fins again I'll have to let you know- but I'm taking the bikes and rack off for that one!
Hitch extension in lower position...to give you an idea of what I'm saying
The bikes and rack are in way more harms' way than the tire and I've yet to (knock on wood!) bend a wheel or damage the rack due to a hit. Break a few rubber straps, yeah, but I was a saggy bottom with toasted Billies. This year I am un-saggy with new Tokikos!
I am currently having a hitch rack modified to work better when wheeling....