How can I go about re-installing the pitman arm correctly onto a new steering box I'm putting on my 85 wagon? The teeth on the steering box do not seem to have any that indicate exact alignment (ie a tooth that looks different than the others).

I was thinking that as long as the wheels are straight (being up on a ramp) and the steering wheel is straight, that if I can figure out how many rotations the box turns at the top end (where the steering shaft goes into), I can approximate the half way point and then mount the pitman arm (already connected to the tie rod and center link) with the box, though I would imagine it might end up being off by a few teeth on the pitman arm. I'm not sure if that matters much, or if there is a better, more exact way (and yet practical with one person) to go about it.

Ideas?