The axles need to have a toe-in angle of 0.07 degrees. The kit came with at spacer that you slide over each axle. With the spacer in place, a straight piece of metal can be clamped in front of the axles. This sets the angle.
As other builders have mentioned, additional spacers are needed to keep the metal post from contacting the upper rod.
I knew all my weightlifting would come in handy some day. I was able to use a metal post from my (not currently used) weightlighting rack to set the toe angle.