Ok first off i want to say i got back from the Dyno shop friday and my camaro laid down 320RWHP/427RWTQ with my 383. Here are some of my specs:

383ci
Lunati hydraulic cam (I think around 305 duration and .580 int/exh lift)
AFR 195cc Heads with Crane 1.6 RR
Edelbrock RPM Air Gap
Speed Demon 850cfm w/ vac. secondaries
MSD 6AL w/ Pro-Billet distributor
700r4 w/3500 stall and 3.73 gears

My thing is i would of thought my HP numbers to be more. My spark plugs are black and it seems like on the graph it wasnt getting enough fuel. The guy said it looks like it was leaning out and was about 13.1 Air/Fuel ratio. Im not sure if my secondaires were opening up. Would it be best to get an 750CFM w/ mechanical secodaries or an 850CFM w/ mech. secondaires? I was looking at either Demon's Race series, Proforms 850cfm, or QuickFuel Technology. Im not good at carbs so any input would be great. I would like to get in the 400RWHP range if possible which i think should be. Thanks again for any help

 

i'm running a 850 holley double pumper and I'm pretty happy with performance. My buddies chevelle has a 850 race demon on his and that's a nice carb as well, he drives the car to and from shows with no issues. Each carb has different features, I'd suggest looking at them online and debating what will work best for you.

 

well i usually just use the car for the weekend and have fun with it. I just want to get the full potential out of the car so i dont care about gas mileage or anything like that. I just want something thats not too expensive (like no more then $650) but is a great race carb. I've been thinking about the Proform so far, so we'll see. I get paid this Friday and need to decide soon!

 

well be sure to lets us know what u gte cause i am kinda in the same boat as you. i am running a 850 d.p. carb and i have 67 jets in it all the way around it and the plugs look great but seems a little low on the jets size to me so i really want to try a 750 at the track to see if the et's go down. i know a guy running a 650 i think its small but he gets to the h.p. and tourque faster than with the bigger carb and only loses about 6 hp. his motor has been dynoed so this is actually numbers. hes on this site his screen name is dialed in. well lets us know.

 

I would get the 850 with annular boosters part #ho9380

 

Annular discharge boosters are good. A larger carb won't hurt anything as long as you have a good booster signal. Thats really all that matters. There are alot of little tricks that can be done.

Id suggest:
annular discharge boosters (the carb shop has some nice ones, though they can be spendy (The Carburetor Shop - Custom Carburetors for Custom Engines)

A good signal is all thats needed, problem with smaller carbs on a bigger engine is, it gives you the right signal, but at the expense of higher end HP. Specially if a dual plane intake mannie is involved.

hope you get it worked out man!