You will note my reply to a somewhat similar thread you started in 'Roadmaster' section. The only thing to add here is NO FW will have "posi". And, any and all B- bodies that do have factory posi will be the non-rebuildable Auburn type LSD.
Let us know what bars you find on that Cady. As I mentioned in the other thread both bars on my regular FWB were smaller than the Impala SS takeoffs I swapped in. And, notably improved responsiveness over the Cady factory bars.
\'96SS SOB: SSRI, Herter Tune, Tri-Y II, , 3000 Edge, F/HO bars, METCO extendeds with CV MMC, Bilsteins, currently Vredestein Ultrac Sessanta (315/35 rear). Finally, wait for it... LT-4 knock module!
\'96FWB BUW-Butt Ugly White: PCMPerformance tune, HDFA w/ swissed filter, 1/2 SLP s.s. catback with H- and Flow Super 50s, oem opti rebuilt 3 times, SS Bars, METCO LCA, Airlift 1000, Monroe SS, PowerTrax No-Slip, CTS wheels with +1 rubber. Finally, yes again... LT-4 knock module!