mine was definitely not repairable with washers....the center pin was wallered out... i will take pics the next time my front diff is apart...
i think a normal person with a relaxed driving style the "lunchbox" lockers would last a long time on the street, you just have to keep off the throttle in the corners (its how i drive, fast in corners slow on straights lol)
is the detroit your running a true trac ?
I'm running the full detroit.