On the T/A box, the "Fast Ratio" factory pitman arm has a keyway ... so.. it'll only fit on the box correctly with the splines. However, I've heard the aftermarket fast-ratio pitman arms do not have that keyway which requires you to determine the correct location... they should eventually fix that matter once and for all.

The hitting of the tires against the frame rail (typically at the rear of the tire) is common for lots of Mopars... not that bad of an issue.... pending the rims and tire sizes that are being used.

You should also be installing a longer C-Body Idler arm... (~1970 Fury, etc)... so to correct the turning radius each side (the factory never did it correctly... an oversight that allowed one side to turn more than the other side when using the T/A box with its longer "fast ratio" pitman arm. (NOTE: ALL aftermarket "fast ratio" IDLER ARMS, as advertised by the sellers, etc, are simply ~1970 C-Body idler arms... always has been, always will be... never "created" or designed by anyone.)

Mopar Mitch "Road racers and autocrossers go in deeper and come out harder!"... and rain never stops us from having fun with our cars... in fact, it makes us better drivers! Check out MOPAR ACTION MAGAZINE, August 2006 issue for feature article and specs on my autocross T/A!