The price of the rebuild kits has gone up. Still, the rebuild video that I saw was done on the car, so the cost of having the differential/ring/pinion set up is saved (which can be a lot of $$).To do a full rebuild of the frictions and steels in the Eaton cost as much as the unit cost new.
My favorite differential... been following that one for MANY yearrs. It was created in the 60's (50's?) and works on the idea that a screw type gear can turn a regular gear but not vice versa. [Look up Dual Drive Differential. The company and production rights have changed many hands over the years. My favorite factory installation was the in the Vector... sorry, rambling again...]If doing it over I would consider a Torsen which uses gears to somehow accomplish a posi effect without clutches to wear out.
It splits torque up to 90%/10%. It works fantastic in some applications (road racing) and not as well in others (drag racing).
Thanks for the additional info. I remember that it worked for some and was disastrous for others. I almost did it at one time, then came other priorities...The lockers that fit an open diff put all the HP through the crosspin. Some have luck, others break the pin and split the whole axle case wide open and they will not handle as well as a posi.