Traction problems

I am a fan of the SS springs, and they work! I think your shocks are two short. SS spring perk up the *** end a lot! stock length shock will bottom out and eventually tear out the shock mounts in the floor!!!

Jack up the car by the bumper or jack stands on the subframe so the suspension droops, undo you shock and find out how much more travel you have in you shock(I bet it's 0) you should have several more inch(at least 2") more travel, as the eng torque will stretch them SS spring even more, under load!

look at your launch, keep hitting the stop button so that you can look at it in little pieces. spring just start to push the body up and then it stops.....tire starts to spin. I could be way off, but if it was me, that would be my first step.

I run SS spring on my E body and the *** end is perk up just like yours. My lift at launch, when i had a 340 with a 2800 stall, was probably 3 time as much as you are getting.
Ok i have flapped my jaw enough.:D