Well, I didnīt have Bp diffs here, it was some savage x 4.6 diffs, they have a higher tooth count than the BP diffs butt since the BP diffs have bigger tooths I think the final size of the ringgear is similar, Itīs simply a much bigger gear than the gears that the lst diffs are using.
So... I simply shimmed and installed the Lst diffs with some steel dogbones and other goddies, Iīm running my slipper completly locked and after 20hours we are still going strong :).
And I didnīt have to remove much material from the bulkheads at all, where the material is removed isnīt were I use to snapp my bulkheads anyway.
The diffcup from the savage fits on the lst cup and vice versa, the only difference is that the lst cup is sligthly slightly shorter, maybe itīs a good idea for people that is stripping the intrenals on their fluxes to use a lst cup, and for the Lst owners that are stripping internals to use savage internals instead since they are a bit thicker and would make the gearmesh tighter.
I didnīt mount it all up tho, so Iīm not 100% sure that it will fit, but I thought it might be a good idea since you have a limited space to shim the internals on because of the pin that the gear sits on on the output.