Check out this link:

http://www.currieenterprises.com/htm...irdMembers.htm

The 9 inch is the poor man's quick change. You have several ways to go.

When the time comes to pull the diff, you will learn lots when you pull the axle.

Big bearings or small, and 28 or 31 spline.

I'd guess you have a 3.00 or 3.25.

For limited slip, you can go with the Ford limited slip, which is the clutch pack deal, and which can be beefed up.

Or the Detroit Locker, which is strong but clanks and bangs and barks the tires around corners sometimes.

For either you have to rebuild your carrier (not for amatuers) or

--get lucky and buy one that doesn't howl

--buy one from someone who knows what they are doing. (Currie and others)

I paid about $450 for an open 3.50 about 10 years ago. Took them 5 diffs to get one that didn't whine.

These are easy enough to change so it depends on your tolerance of doing this more than once or parting with $500 to $700 or more.

Happy motoring!