89' GMC Suburban, 20's in the front 22's in the back?

[jathur02]

My truck is dropped 5" in the front and 6" in the rear, with air shocks on the back. It was like this when I bought it, and even with the max psi in the rear air shocks it still appears to be a little lower in the back. It has 20's all the way around now, but I'm thinking of either doing 22's all the way around (with possibly a taller tire in the back), or 20's up front and 22's in the rear. I'm hoping this will bring it up some in the back or give it a better stance overall. I've been trying to find a Suburban like mine with this setup or someone that has done this before to give me some advice before I pull the trigger on a set of wheels and tires. By the way, the 20" vision and tires are for sale in the pics...less than 900 miles on them. Thanks in advance!