Bought my 3.42 posi cut out of a 87’ GN in 99’ for $100 by a junkyard who had no idea the black Regal was a stripped GN or maybe even the 8.5” values if they did know. Ran it as is in my SS with just a fluid change for almost 20 years, had it rebuilt with a fresh posi unit, Moser Axles in 2017. Kept the nice shape posi unit out of my 87’ GN rear. About 200k miles on it but my builder was interested in buying it, still looked that good. Kept it in case I find an open 3.42 for my LS cheap(not likely).
Bought a 86’ Turbo Regal 3.42 non posi for $275 or so in about 2003, little crusty but solid, ended up selling it to a friend for $350 a couple years later. He had it rebuilt and a posi unit installed, still running it in his SS.
Got my last 8.5” 3.73 posi from a 86’ 442 3-4 years ago for $600, sold the aluminum cover for almost $100, I just installed that in my wagon last weekend, sat around awhile before I freshened it up.
Deals can be had but I wouldn’t count on it. If you need an upgrade your paying either way. Pros/Cons to any choice. None of my cars have 600-800hp and never will, so a 8.5 is plenty good.
