The 9' is becoming scarce around these parts. And that has made the price go up quite a bit. You know you can get those 9' inch rearends shorten don't you? If you find one at the junkyard these days, you are a lucky man. The Granada, and Maverick, Versallie are there but that wonderful 9 is gone. The Versallie will give you disc brakes if you find one. Well I did have a buddy who was lucky enought to run into a 9' for 250 bucks and that came out of a junkyard. But unless you are running a lot of horse power you don't really need it. Plus a 12 bolt will handle a lot of horse also. Anyway checkout this page it will be of help to you.
http://www.chevytrucks.org/tech/ifs&rearend.htm