On launch it will drop on the right rear, which is true. If you want to fix it then you need a better suspension. Put one of the HR bars on or something like it. Helwig also makes a decent substitute. The issue is the rear springs and frame flex when it gets traction.
One thing I'd really suggest it to measure the ride height. It's suppose to be 10.625" to 9.5" measured at the rockers behind the front wheels and in front of the rear wheels. It's it's below 9.5" the springs are worn out and need replacing. If the rear of the car is leaning to one side same issue. Also check the body bushings and I'd bet that they're dead by now.