It appears to be a standard Saginaw box that was used for many years in GM vehicles. The car box mounted inside the frame and the truck box mounted outside the frame on stock applications. They more than likely assigned their own number to it as they are probably new castings. The installation procedure you are refering to has been around for a long time and would likely use this box.
I'm partial to the Toyota box, it's compact and has the steering sector positioned similar to the stock box. It still requires some work, expense, and modification or replacement of the column. It's as close to a "bolt on" as you are going to find.
Fred
Last edited by rfs56trk; 05/09/2008 4:14 PM.