Hello. I'm going to replace a Holley 750 Double pumper with a vacuum secondary carb and wanted some advice on size/model.

Here is some info on the car/engine:
1. 405 HP at the crank
2. Intake Manifold is a Dual Plane (Edelbrock Performer RPM Air-Gap).
3. Heads: PRO FILER 195CC ALUMINUM HEADS 2.02/1.60
4. 10:1 Compression
5. 1979 Monte Carlo 3500 lb (est)
6. 3:70 Gears
7. 2400 RPM Stall Converter
8. Automatic Transmission (700R-4)
9. 383 Stroker
10. Redline 6600 RPM
11. Mainly street driven

Using the Carb equation: Cubic Inches x RPM x Volumetric Efficiency ÷ 3456
((383*6600)*.90)/3456 = 658.28125

I had been HEAVILY looking at the Demon carbs, but called Ron recommended the Ultra Street Avenger. Based on that info, I nailed it down to these:

1. 650 CFM DEMON
A. 650 CFM Speed Demon Carburetor – Down Leg Booster
B. 650 CFM Speed Demon Carburetor – Annular Booster

2. 750 CFM DEMON
A. 750 CFM Speed Demon Carburetor – Down Leg Booster
B. 750 CFM Speed Demon Carburetor – Annular Booster

3. 670 CFM HOLLEY
A. 670 CFM Ultra Street Avenger Carburetor – Straight Booster

Do you need any other info?
Do you have any advice?
What booster should I use and why?
Thanks again, Russ