A supercharged hemi is a whole different animal. I've seen supercharger hemi's on Bartons dyno making 1500 hp.
A local guy has a Challenger with a Barton hemi under the hood. He's a regular at car shows. I don't remember the cubic inch but it made 650 hp on the dyno. He displays the dyno sheets and his time slips in the window at the car shows. The car ran around 11.50's in the 1/4 mile. That was with a pair of slicks and a Pro trans automatic transmission.
He is happy with the performance but 11.50's is kind of slow for 650 hp.
The car should have been able to at least get into the 10's.
If Barton dyno'd the motor I'm sure you have the horsepower but getting the car down the track is a whole different ball game.
I wasted years trying to get my car to ET with SS springs but this year I switched to Caltracs and made an instant improvement and then the final addition was double adjustable rear shocks. Until I threw away the Rancho shocks and switched to double adjustables I could not get the car to ET with the drag radials. It will take time to figure out what your combination needs.