Yup, my set cost me $100 and a set of 4 cylinder 4.10's...
Warning, tech....
There are 2 vac lines on my 94 ADD front diff, one locks and the other unlocks, it does not seem to need constant vacuum to stay locked, although I'm sure I'll just plumb it into the manifold vacuum so it's always trying to lock...
Se my above post. Take the time to swap out the long tube and install a seal on the ADD unit. It keeps one wheel from turning the carrier constantly and allows you to use the needle bearing tube for longevity.
It's a good swap; no doubt..