The Stovebolt Site Forums The Parking Lot Big Bolts 1953 GMC, Detroit, Roadranger, disc brakes, and PS!

With these two links to start with
The first one on page 22 and 23 explains how Ackermann Geometry works.
The second link on page 19 gives the choices of steer arms that work with these spindles.
Using common medium duty axle is an advantage because there are lots of tie rod and steering arm choices available; these axles were used by many manufacturers in various length trucks. Which is not the case for say a pickup axle that only came in one width and one or three wheelbases, so only a few if any choices.

From studying the Ackermann Geometry:

In this case the wheelbase is 178.75" and the "King Pin Index" is 53.875"
Some trig reveals that the tie rod ends need to be set in at an angle of 8.57* so they point to the center of the rear axle, this is the "tie rod angle".
With that info I can do the math on the available tie rod arms and have determined that part numbers 080TR107 and 080TR108 are the most likely candidates.

I'm now going to call Spicer and see if they can confirm my findings.... Some of the measurements were tricky to make on the spindle to relate the center of the king pin to the reference point on the tie rod arms they give in the parts list. an 1/8" error is about a degree off on the angle so I need to get that right.
With luck they'll have more detailed info (than the parts book) readily available.

I am confidant on my KPI and wheelbase measurements, and even if I were off some it has little effect. For example a 2" mistake on KPI changes the angle by only about 0.3*, or a 2" wheelbase error makes only a 0.1* change.

Grigg