As long as I don't have XXX4 or XXXS I won't tell you if you can put slipper from 4 to S. It just doesn't make any sense to me. You don't need slipper for TC.
Losi makes 48DP spurs as well (it just took me 2 minutes to find it on losi.com page) -
http://www.losi.com/Search/Default.a...20xxx-s%20spur