Agreed - Without a tire swap the only other thing I can think of as far as suspension are no-hop brackets...
https://www.summitracing.com/parts/qa1-5213/overview/
These were used on my partner's '66 with success for a 1.51 60'...he had less hp and was closer to 4000 pounds, but did use slicks for those runs. Unsure with those tires what the outcome of a higher stall converter would net.
Is this you at the 2:19 minute mark?