You may want to give it a try with shocks at 9 and at least 2 full turns of negative pre load. When I went from a 452 to my 542 RIP I had to do that after trying everything. I put an air shock over the pass wheel with 65 lb in it and just kept backing the bars off till it launched nice and smooth. Went from 1 1/4 turn pre load to 2 1/4 negative and walla that was the ticket. Course that was foot braking and it went 1.400 short in my 3620 GTX
then after the 542 went to Big block heaven went back to a 452 and back to about 1 1/4 turns pre load still using the air shock keeps it even leaving and can set bars the same no need for extra flats pass rear.
now I went from a 4000 stall to a 5000 stall and it's a bit different again kinda chasing it a bit still? Yours almost looks like it hits and kicks back instead of lifting front good and that is what my 542 did only even more dramatic.
You may have to set it so you can get in the top hole if your not on an A body.

( I have one air shock left?? LOL!!)