does anyone know the difference in pitman arms??

72bluNblu said
67 and 68 pitman arms are the same. Only the idler is different. You got a pitman for a large sector steering box.

Steering Linkage

And while I won’t say this is exhaustive list, the folks at big block dart didn’t see to include a part number for a big block pitman arm...

Moog/Chrysler Suspension Part Numbers

There is a discontinued reference for 383 in my Moog book.