How much improvement will I see?

I would change the shocks first, then sort out how the car launches. The car has the capacity to really stick the tire with the power your are throwing at it. You could end up needing more flash rpm to get the most out of your combo. There is nothing in your combo that makes traction hard to achieve. I’m making more power flashing to 3500 with 1/2 the tire. I am a bit lighter, but I could see you needing more flash rpm to help get her moving. The years of higher flash equaling high % of slip at the stripe are gone. I’m slipping 3-4 % at the stripe. Also my 904 PTC 9.5” converter cost $700 US about three years ago.