305/50R20 Grappler's before the drop kit was installed:
It would drive me nuts to have a 2WD without at least dropping the rear a couple inches to level it. I Hate the stock Rake!
My drop was actually pretty tame, and mostly meant to level it out.
The front only came down about 1", the rear about 3"
Stock height, stock tires
Stock suspension 305/50R20 Grappler's
Dropped to almost perfectly level , about -1" front, -3" rear With 305/50R20 Grapplers
I've seen guys run the larger 305/55R20's (without spacers) The 305/55R20 Terra Grapplers are 12.4" x 33.1" (my 305/50R20's are 12.2" x 32.1")
But that size was on back order when I was shopping, so I saved $75/tire going down a size from 33" to 32".
The handling is better (lower sidewall) and as HEMILANCER mentioned, my net gear ratio worked out a little lower for better performance.
They also weigh about 6 pounds less for better fuel economy.
I'm more about performance anyway and I even swap to a lower dedicated set of 27" tall drag radials (295/45R17's) for the track...
My net effective gear ratio drops from 3.55:1 to 4.30:1 = FAST! a half second faster than stock 33's
Here's a few more snap shots of the 305/50's just prior to installing the drop kit...
If you're really set on 33x12.5's, They will work with a 1/4" wheel spacer. It's been done several times by other members already.
Some have even mounted 35"x12.5" tires on stock wheels (4x4's) after a front level kit but most, if not all, use 1/4" wheels spacers.
I had a pair of 1/4 spacers handy just "in case" I needed them because I knew it might be close.
I'm no stranger to larger tires either
...almost always try to stuff the largest tire I can and check thoroughly for rubbing.