Pitman arm size

[Sadie_the_66]

I bought a new pitman arm for my 66 sat with ps, and when I went to go put it on it was too small for the spline on the box. I highly doubt the box on my car is the 1 1/4" spline and the pitman arm was just barely smaller than the shaft of the box. Could it be the part was made wrong? I checked oer and it said that that exact part number should be 1 1/8". I don't want to order the wrong part again and I could use a little advice.

 

[R/T Boy 67]

Measure the shaft at the top, just under the seal, and then you will know. The car probably left the factory with the 1 1/8" shaft, but that was a long time ago.

 

[Don67Satellite]

Had a similar issue when doing my suspension. Bought the Proforged 103-10030 pitman arm as I ASSUMED it should have fit my car, but found it was too small for the shaft. Seems I had a 1 1/4". As luck would have it my suspension guy said that it looked like the pitman was changed at some point and was in great shape, so didn't have to source another one. The mysteries are part of the fun.