not a 396 just a 323:(

more gear\\\\ 4.30 \4.56 \4.88
If you want more power, then go with a higher stall speed.
3800 to 4000 stall converter would work good.
Sounds like your trying to go fast.
This is like a race set up ,but that's the kind of cam your running.
Your cam will make peak torque after 4000rpm's.
Try a 9 1/2 dynamic converter down the road, but first change the gear.8)