questions on my '79 Versaille 9 inch, and suggestions needed.

[coyote11]

I recently traded emails with Randy from Performance Unlimited, he stated that the rear that I have is a 9 3/8 rear, and that I should be careful with it. What is that about, anybody know? I also did not get the rotors with it, but that is alright being as the b0olt pattern is 5 on 5 and I need 5 on 5 1/2 for my EB. I would like to have the axle narrowed and run a home made full float with Chevy Dana44 parts from the spindle out, Randy had mentioned this conversion on EBML I believe. Any pros or cons to this, or does anyone see anything that might get in the way of this becoming reality? Thanks in advance. Does this housing use a standard 3 rd member? If so I do not see where a problem would be, even if it is a 9 3/8, it is the late style stronger housing. By the way I will backbrace it and run an ARB with 31 spline axles.