3450lbs b body here:
12.75 to 13 lbs air in slick.
rear shocks full tight on rebound
lower front end travel is a blessing for you.
we leave at 1800 to 2000 rpm depending on track- foot braking.
5100 stall

wheels up and carrying a bit.
Suggest putting car on 4 corner scales to dial up best weight distribution you can.

My guess is car should be somewhere between 11.5 and 13.5 lbs air pressure.
just guessing as we dont know much about car, if your on a trans brake , converter/clutch.

secondly- see if you can get someone to shoot video of car leaving- tire video and then one showing chassis working.

Just my thoughts.