I have a rearend for my 86 bird. The car now has an open 273 and I have a 373 that a guy gave me but he said the clutches were bad in the limited slip unit. Can these be replace or should I just look for another unit. The gears anre in good condition. I have called a couple of parts stores and the gm garage and they said they could not get the cluthes. Are these rebuildable. I did a search and could not find what I was looking for. Thanks.

No the clutches are non-replaceable.
You'll need an all new differential assembly. $400-$500 or so.

thanks thats what I was afraid of.