Just took my R-200 in to a shop today to have it welded. I am building my z as a road race car, so I figure I can skip on spending $ for LSD internals and just make a cheap spool. I don't see many Le Mans cars running with LSD...
streeteg - all that needs to be welded are the spider gears. All four corners on each side. Its better to connect the welds and fill all the gear teeth together. Just make sure to degrease the whole casing before, and use a whole can of brake parts cleaner and remove all the weld beads afterwards.