On my mild 496 I run an old Edelbrock CH4B and a Holley 750hp mech secondary.I have run it with an 850 but the heavy pig has better throttle resonse with the smaller throttle bores.

When I was running 3.23-3.55 gears and smaller headers it ran strong with a modified 750 vacuum secondary with the choke horn milled.

I have run the street dominator as well but I prefer the better idle and low end of a dual plane intake with my big ol girl.