New factory LSD, 4.09 ratio (improves acceleration with about 15% more torque, instantly (could be more depending on ratio.). Believe it fits XJ40 and X308 also, although the latter normally use a centerline diff?
I had an XJR6 one time with traction control AND LSD and it’s a great combo. God for chump car racing? Have flywheel and some other parts to convert auto to manual. Diff is $350 obo.910-398-3620