Red line:
Either the Manta Ray or TA03 ball diff should work just fine with the Integy or Tobee gearsets.
Nova F1:
The Shoe-Goo trick works great to lock up the diff but according to the Tamiya folks this also essentially creates a spool, which is not made for the car and is therefore illegal for TCS races. Same thing with using a TA03 one-way diff in the front- not legal for TCS. Trust me, this has been tried before...both work well but don't make it through tech inspection. On the other hand, a really tightened down ball diff is perfectly legal- it just needs to have some discernable diff action.
Later
Doc