legacycentral bbs

I am going to have my local mechanic switch out both the tranny and the rear diff in my '90 legacy. I know what to expect on the tranny swap, but how long should it take to do the rear diff?

Also, I am looking for a TCU for the '92 tranny, if anyone has one please let me know. ( I dont really know what this is, but I hear it could help my tranny function at its best.)

Thanks!
Bret

The TCU is the Transmission Control Unit. It's a computer that controls the auto tranny. Tells it when to shift basically, without doing a lot of work you can't even start the car without it.