BTW, it looks like you have at least 100% antisquat.
See how the seperation is about the same. You can tell you are leaving as there is a wrinkle in the tire and your front end is moving.. You are transfering weight to the rear.
How much upward travel do you have in the front from ride height to where you start to take weight off the front tires? The more you have, the more weight transfer you are going to have.
Also, I know it might be hard to get the rear lower, but, if it were level with the front, under launch, you would end up with more weight on the rear tires. I see you have lowering springs in the rear, I'm assuming you do not have blocks there as well?