Rear Axle Widths

Does someone have the measurements of the 8 bolt rear axles. From my basic measurements it looks like my current one is about 2" to wide per side for my bus. 88-98 3500 chassis

This link has pretty much everything you want to know about 14 bolts including all widths available.
its a little long but well worth it.

http://www.pirate4x4.com/tech/billavista/14b_bible/index.html