just out of curiosity, how much power can these diffs cope with?
it's a 2.92:1 open wheeler borg warner 8 3/4? diff.
im running a worked 351c with 2500 stally in a C4, just wondering how much life is left in her.
she has a bit of a clunk, probably has done over 200,000km previously.

Probably not much longer

My XD had a open wheeler 2.92 and it was fine until one day of a little bit of abuse (read flogging the s**t out of it for nearly a day of motorkana), it developed itself into permanent lockup, fun except for a unplanned 360 when I went to do a fast turn around. It died so after that.

I have also had a XF 25 spline axle LSD that didn't make noises at all, no warning and bang, just from a little burnout. (Read 351 vs heavy car and crap diff not a good combo)

Basically they are crud if abused, nearly last for ever if not abused, it will most likely be a 25 spline, two pinion job, XD-XE factory 351 are fitted with LSD 28 spline axle (9" size axles), 4 pinion, if you are after the same ratio go for one of those, rare XF had 4 pinion centres and sometime in EA they all went to 4 pinion 28 spline axles.

get the backlash adjusted and new wheel bearings and it should last quite a while

well i wanna upgrade to a 9in with 3.23:1 LSD disc brakes.
this one has drums, and the car has just had a full rebuild (besides diff/rear bushes/rear springs).
i just want it to last a few thousand km, i dont' intend to reco it, just put new oil and a seal in it.