67 Chevy truck...trying to put power steering back on.

[sbrban]

This truck had it originally but someone took it off-I'm assuming it was a leaker.
I purchased a power gearbox off a guy but it was missing the pitman arm. I ordered a new arm and now the fun starts...the box I have needs a it man arm with a pinch bolt,not a nut. I looked at my 72 4wd Burbank it takes the pinch bolt. Well, apparently this style pitman arm is made of unobtanium.
So I'm wondering-are the 4wd gearboxes the only ones that use pinch bolts? And why is it so hard to get a new arm for them?
Should I just buy a reman. 2wd gearbox and sell this pinch bolt style? Thanks for any help!
Mike.