Is 950cfm gonna be too big?

Precisely. Ran a 1050 2 circuit Dominator, on a well massaged 396. More response,and torque everywhere. There was a stock low compression 440 dyno test. A 750 Edelbrock CHOKED it. Swapped a 850 Holley double pumper on,picked up 20 ponies. You added 70 inches.....