Hmmm, I don't know about the limited slip diff. On a real car, we would weld that for drag racing.. hehe .. But that would be a waste of a limited slip diff. I thought limited slip diffs on RC's are the ball diffs. So you have a limited slip diff, besides the ball diff that you mentioned? It sounds like that it would be easier if you just shove in some glue on the regular planetary diff, don't you think?