[MidOHasp]

I'm currently running the BG Speed Demon 750 (double pumper) on my 408.

I'm running a decently stout cam (.576/.580 I/E lift), 10.25:1 compression, AFR 185cc heads, and an RPM Air-Gap intake (built this one for torque. Would've used Vic Jr, 205AFR's and a little bigger cam for HP).

The BG S/D 750 D/P is just enough carb. We went up a couple jet sizes and put in a bigger power valve on the dyno...not a ton of difference. 508HP, 544TQ at flywheel.

Tony, the guy who dyno'd my motor, hates the BG carbs. Said he'd put a Holley 750DP up against it ANY day and gain 40HP. But he also expected us to come in about 40HP shy of where we did. He said that every now and then you'll get a good BG carb, but they are inconsistent and he would never use one on an engine he personally built. FWIW.

I like it, it runs well, and it looks good, too. You should be fine with the Holley or BG 750. That's most likely enough CFM unless you are going to run 7000RPM, which I would NOT recommend with your setup. Your engine will likely make less HP at 6K than it will at 5500, but will still make good HP to 6000-6300 probably.

Just my $.02