Your manual box has a smaller shaft and the manual pitman arm won't fit anyway.
The joint on the end of the Pitman is like a tie rod joint with a grease fitting. But it doesn't swivel, it just rotates like the idler arm does.
Later cars had this joint on the center link so when they wear out the center link is replaced, that's the way the Pitman arm is on the PS box you bought.
you didn't mention it, but most of the late model boxes have the pitman arm going the other way, it's no problem to point it to the front when installing the new one.
You can buy a new pitman arm with joint on the end. Classic has it under #RP20138 $79.95 for slow std steering, and #RP20526 $119.95 for Z/28 with fast ratio steering.
I'd get the fast ratio one and if your idler arm is stock, replace it with a Moog idler #K-6099. This idler is a little longer than the stock one, but shorter than the 67 idler arm and should work with either pitman you choose.
The long idler that really matches the length of the long pitman is #RP20227 from Classic, it's $89.95.
Try a puller on the PS Pitman, you may have to heat the arm to get it off, I did on one of mine.
I've got some photos of these parts on my firstgen page.
Check my web page for First Gen Camaro suspension info:
David's Motorsports page
First Gen Suspension Page
67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Can Am Vintage Racer
[This message has been edited by davidpozzi (edited 01-13-2001).]