We got a guy here with almost the same set up as you, Demon,all steel +glass bonnet, street/strip car
SSsprings,3.91's, 10x28 Bias, Hughes 3500 verter, prob under 10:1?
Stock J heads 2.02/1.60
Mild 340/416, mild hyd. .474/495"
TR with 2 x 650DP's.
Shifts around 5600, traps around 6k.makes around 420fwhp
here's a shot of his best run, has been 1.55 60 at the same ET. Its very soft on the hit not like yours.



I would keep the gears and put a taller tyre on it, 4.10's would make around 200rpm difference in the traps, I would also at least try a bigger carb.
I went 1.8 10ths quicker on my hyd. cammed 340 street/strip Cuda with a sorted 850DP over the 750DP that it came with.
Just for a bit more info.