355 Gears - Possi Giving Out?

[08ACRVTEN00GTS]

I am running 355 Gears installed by Heffner - I was doing a burnout the other day and I felt the posi traction let loose to one tire, the rear end was fishtailing. Today I took my car out and hit 2nd gear pretty hard and it seemed to do it again - I was going straight ahead. Went home, did a little burnout in my driveway the posi seemed to work fine. Anybody tell what is going on, it did not feel normal to me at all. I can do donuts in my GTS in a parking lot all day long in possi. If anybody has any input I would appreciate it, I will call Heffner also.

 

[Viper X]

If you still have the stock diff, buy a Quaife. The stock diff is very weak. Multiply the torque and it will fail. I went through two of them before I bought the Q. Now, now problems.