just fitted an SC10 diff in my B4 using the parts listed previously. it all went in very well indeed
(thanks to Marc from MK Racing)
using 1000wt associated diff oil it felt a bit tight to start off with but after a quick 5 min blast around the garden, everything has freed up nicely. it feels like a tight(ish) ball diff at the moment but will free up a bit more after racing tomorrow i would think.
i'm happy so far but we'll see what it goes like on the track....