I've currently got a BA M78 LSD sitting here, waiting to go into the car. Trying to get 3.9 gear ratios for it, is quite a pain though. I spoke to a couple of places, and they say just get gears from an AU IRS LSD, as they are the same diff but are more stronger as they use 4piston, rather than 2 like the BA's.

If this is so, would I be better off just getting an AU IRS LSD (seeing as it's a million times easier to get gears for), or just stick with the BA Diff?

Interested in this as well. I have both diffs and have been wondering that myself.

Yeah, I found 2-3 posts that said the same thing. Just wanted to confirm.