This is a pretty neat, but not cheap tool, to figure out wheel size, backspacing, width, etc. Made by a gentleman named Mike Keller, who owns a company named Verified Fabrication. It is a very well made and thought out design. The tires (when I get them) actually mounts to it, and you can move your suspension through it's travel, with wheel turned (up front) and see where you might have clearance issues. I figure a $400 tool is a lot cheaper than $2000 wheels I can't use, if I got the measurements wrong.
This was the only issue I ran in to with the tool. Of course it's not designed necessarily to use with the IRS suspension. I called mike, and he told me the tool is thicker in that area for strength to hold the tire, which is what I thought. So I can roughly take away about 5/8" from the thickness, and it should be good to go with 19" wheels. If I set the slides to 20" wheels it clears, but I don't want 20's and rubber band tires..lol
