I went way overboard and did Torsen diff front, center, and back in my Inferno 7.5 BL. I know that recommendations were to not do the back wheels, but I had to find out for myself. Having the Torsen in the front and center is awesome, but I am seeing how much of a pain the rear one is, I can't kick out the rear wheels any more on any surface during a turn.
The effect of hitting the throttle during a turn it that it totally straightens the car out and the car wants to go in the direction that it is pointing. I am considering putting a regular diff back in the rear wheels so I can get a little kick around turns, since now all I can do is let the car drift through a turn completely before being able to go WOT.
The benefit I have found though is that the acceleration is rocket fast, there is zero wheel spin when I nail the throttle. I guess there is always a trade-off.
I haven't had any problem with advanced wear on the diffs after bashing them very hard for almost 6 months. I do follow the instructions of lubing the diffs after every 2 - 4 hours of runtime.
I was thinking of taking that Torsen from rear and putting it in the front of my LST2 BL, but reading what I am here about trucks I might hesitate as I have that running great on standard diffs with oil 20K front/ 40K rear.
Anyway - sorry, I got into a rambling post there - just trying to share my experiences as I didn't have much to go on when I made my purchase.
I got mine from amainhobbies.com and they were a bit pricey. I have found after the fact the
www.rcmart.com sells them for $75.90 each.