Idler arm confusion

If you have later model power steering, you may need a pitman arm that Chrysler never produced. I recall reading somewhere that the aftermarket now offers a pitman arm that will connect late model large spline steering gear to early model center link.
"If" word again... Easy learn is measure the hex nut that holds the pitman arm on the steering gear. If it is 1&5/16 That's the later model steering gear and you would need a special/oddball pitman arm to attach to a early model center link.
If that nut measures 1&1/8 for manual and power steering of earlier design.