727 or 904?

First things first: How do you know it's broken?

After doing a small burnout the trans has had issues. If I put the car in Drive it will just rev and the car will rock about 1/2". I have to put the trans in 1st and manually shift the car to drive it. It also wont take a lot of power. If i give anymore than 1/4 throttle it will not go. It feels like it is slipping or driving through the converter. The fluid looks brand new too.