72 duster 340 pitman arm spline diameter

Working on a 72 duster 340 and replacing the power steering box which was a rebuilt from cardone and it locks while in a turn with a rebuilt from steers&gears but issue is the splined shaft for the pitman arm.
The cardone box I used a puller to take arm off when I went to install on the steers&gears box the pitman arm is to big and the shaft looks like it's about 1/8" smaller (visual with tape measure) .
Is there another pitman arm that will work or different year.