Tuckin' A 22"

i have asked countless people these days... but i will try once more...

I am going to be laying a 88 fullsize out on 22's. I realize that hitting the fenders is one of my main issues to overcome, and with going from a 20 to a 22 it's still some what of a problem... now The question

Back Spacking / Offset. No one can give me a straight answer on this. I am running 20x8.5 inch wheels with a +9mm offset. i am unsure of my backspacing of how this plays into effect, but what would these figures need to be for a 22x9 or 22x9.5 inch rim to clear that pesky fender?

Will it seriously require a modified a-arm? tubular perhaps? or just sectioned? or is it possible to buy a 22 that will fit quite nicely?

in any event, some help would be appreshated from those who know.

Thanks!!!