you are limited to what you can do becuase of the design, buy Yoofington has made an adjustable tca which means you would be free to play around to your hearts content, once he starts selling them I pressume.
Best bet is to pick a number out your ars (just till the wheels are in the middle of the arch, but careful you don't run out of thread)
then drive down to a place that has proper equipment. Its a major hassle to box it all up and start doing it by hand.
Yoof sent me the first draft of some instructions way back when so if you PM him then he should be able to help you out.