Variable Ratio Steering Upgrade Issue

[gringoloco]

Ok, bringing this one to the 73-87 experts, since I'm a 67-72 guy...

My truck has previously been converted to 73-87 front 1/2T suspension with great results. Due to a leaky steering box, I have since replaced it with one from an '83 to gain the benefit of variable ratio and to more easily mate with my serpentine accessory drive setup's PS pump fitting. Once I swapped out the box, the steering wheel was off center and my turning radius was affected.

In attempting to professionally align the truck, the issues I am having are that I cannot keep the steering box (and pitman arm) centered while having the tie-rod ends anywhere close to even-- one side ends up extremely longer than the other. With the box centered, the steering column and wheel are off-center and I lose turning radius in one direction and gain it in the other, the blinkers won't properly cancel, and not to mention the potential bump-steer issues. On the other hand, if the tie-rods are adjusted close to equal, the pitman arm is not centered and the truck wants to 'drift' on the highway due to the box being off-center, and I still lose turning radius, but in the other direction. Frustrating.

Looking at this as a possible parts compatibility issue, the only things that I see that are different between the years are the idler arms and pitman arms. Does anyone know of any geometrical issues that would cause this problem after swapping to the newer steering box?

Again, the problem was non-existent before the variable ratio box upgrade. No other parts were swapped at the time of installation. I see lots of people upgading to the newer box, but none reporting these same issues?

Thanks in advance for any help you guys can provide -Chris


(Moog) Parts info:

'71-'72
Idler: K6096T
Pitman: K6130
Tie Rods: ES409L/R

'73-'82
Idler: K6096T
Pitman: K6142
Tie Rods: ES409L/R

'83-'87
Idler: K6247T
Pitman: K6142
Tie Rods: ES409L/R