Differential options.

[atc40]

I have a Rover engine in my Stag and am concerned about the diff handling the additional torque, as have always believed that the standard diff was quite fragile, although I have had no problems up to now, just looking to improve on it.
Am aware of the BMW/Subaru diff conversions but has anyone fitted a diff from another vehicle?
What is the weak point with the standard diff?
Would fitting an LSD assembly into the Stag casing overcome any weakness?
Any help would be appreciated
.

[Dean]

Do you have the stag gearbox or a lt77 rover box , what age is the rover engine is it a 3.5 or the later 4.6

[atc40]

Gearbox is an LT77, originally ran a Rover 3.5 engine with Hotwire fuel injection and had no problems with the diff, very quiet (Rebuilt by Richard Lane) but have now replaced it with a Land Rover reconditioned 4.2, hence by questions.

[Dorian]

I'm sure there are other differential options with some fairly simple modifications, the BMW route was an obvious one to take in the 1990's because they are really strong with lots of ratio options and good ones were at the time readily available/cheap. This then evolved into the complete chassis transplant.
Is there a reason why you don't want to go that route or just looking for newer options that may be easier and cheaper to source now?
I don't have any direct experience of the longevity of the Stag differential behind the 4.2 but would think that with gentle driving with it might last for some time. I know when I did the conversion it was considered necessary to upgrade particularly with the tuned larger 3.9 or above Rover engines so it was all done at the same time.However my first conversion used the Stag subframe and BMW differential/Datsun shafts and the 4.2/3 tuned engine but was plagued with vibration and the squat at the back on acceleration made the front very light, hence the move to the BMW subframe and trailing arms.
It's always easier to go down a path that been refined over years, but if you have the patience and motivation to do something different and possibly better/more modern thats great. Your skills may be better than mine but my experience is it normally takes 3 or 4 revisions before you get something that your happy with.

[jbuckl]

The E30 or Subaru are the most easy higher torque capacity differentials to adapt to fit a stag.