[Dragsinger]

117X,

"Sounds like" the pitman arm has been modified to allow using the manual gear. [an incorrect manual gear]

Doing so is not necessary. There is a certain GM manual gear that has the same output shaft size as the factory power steering gear.

When proper parts are selected you will have the factory power steering pitman arm and the correct matching manual gear. The manual gear you need as original equipment on many 70's GM products.