I am in the market for a carb and looking to get as much power as I can. I have about $600 to spend. I currently use a 600CFM edelbrock and the top end seems like it gives out on me. I will be taking the car to the dyno on July 10th and would like to get the best results. I only drive this car for fun so gas mileage isn't an issue.
Most carb calculators I see out there say my engine should do fine with a 600CFM carb, but I still feel it isn't quite enough or the one I have isn't tuned correctly if that's the case.

My setup:
383 small block ~10.7 to 1 CR -5cc 2 valve relief flat tops
200cc Summit racing aluminum heads (I think they are brodix clones) 2.02/1.60 valves 64cc
Weiand stealth air strike intake (RPM air gap clone)
Lunati 60103lk cam -268 duration .489''/.504'' lift 1800-6200rpm
Hooker cermaics - Shorty's to 3" y-pipe with magnaflow cat (single 3") and hooker 3" catback
TCI super street fighter TH350 w/10" 2500-2600 stall 3.23 posi

Let me know what you guys think. I read the sticky about how to select a carb and it said vacuum 2ndaries if you have an automatic and less than 3000 stall. You guys agree with that?

 

I'm by no means an expert, but I think a good 650 or 750 with mechanical secondaries. I have a mighty demon and haven't had any problems with it, but lots of people have had them. AED's seem pretty popular. If your looking for all out power, then I'd look for one without the choke horn like the mighty demon I have. Just keep in mind that it will make it a little more difficult to keep running on really cold days until the motor heats up a little.

 

The typical CID x RPM / 3456 = CFM formula assumes a single plane intake and 100% VE. Most engines aren't 100% VE, but the other side of that is a single plane will use all 4 barrels of the carb to provide the flow to all 8 cylinders, while a dual plane intake roughly splits the carb in two. This doesn't double the size needed, but increases it about 15-20% (which is about what a typical non-race engine loses in VE).

A 383 spinning to 5500 RPMs needs over 600 CFM, so you are a little under-carb'd. I'd concur with the 650 to 750 CFM mechanical secondary recommendation. I'm seeing more guys having good results with QFT carbs.

 

Thanks for the tips. I was checking out the quick fuel carbs as you suggested. It looks like the SS-750 would be a good choice.