Oh here we go!20x12 with 33s looks dumb as with anything under a 6"..
And with a 6" there will still need to be some trimming on atleast the valence.
Had an 02 Tahoe 6" on 20x12s/35s and had to crank to the sky and trim the valence just to clear.
A body lift will not suffice at all.. Just save up and do it right the first time.