Saw these last night when shopping
http://www.apexmodels.com/gbu0-prodshow/LOSA4149.html
Assuming it's the 3 deg one.
The TLR 4 deg block comes with the TLR tuning kit for XXX-SCT but can't find a part number for it as a seperate part.
Probably best to try DMS Racing, Darren knows his Losi stuff well