2wd/4wd differ ?

[Ironhorse]

Can anyone tell me if there is a difference between the clutch cross shaft (Z-bar) for a V-8 for a 2 wheel drive verses a 4 wheel drive? I know they are not the same between 6 cyl. and V-8 engine because of physical size difference in block/frame configuration. My connection to GM parts counter says his " book " is not specific except for a "DD" code as in "double duty" cab forward? Greek to me. Need to locate a replacement for my 4x4 as it is getting a bit "weak" and has been welded several times. The metal tube is wearing after 30+ years. Doubt that a ricer would ever hold up that long!