Carburetor CFM

[CORE402]

Hello,
I haven't been here for quite some time, I have been a little preoccupied for the last few months. I have a quick question for you all if you dont mind. I have a 1973 Camaro with a worked over 350, .030" over, SBC with a pair of unmolested 462 heads (camel humps), an Edelbrock Performer RPM intake manifold, a cranecams (HOT) flat tapped cam, a high stall converter, a TH350, and a 8.5" 10 bolt with 3.73:1 gears. The engine peaks out at around 5800rpm. I was thinking on a Holley 750 double pumper. What carb, cfm, and secondary style should I purchase for my engine. Currently I have a 600cfm holley with vacuum secondaries with the white spring. I have a feeling that the 600 is limiting my upper rpm HP. Thanks for any info.

CORE

[Earlsfat]

I think Holley's website has a formula that will get you in the ballpark.

I am wrestling with the same question on mine, but I think I'm going with an Holley 850 DP. I would imagine that with a HOT cam you would want at least a 750 CFM DP, but forget about your gas mileage. I've got a totally different set-up (454, etc) with a 750 CFM Holley, with vaccuum secondaries (Holley 3310-3 if that means anything to you) that's just abysmal for gas mileage, and per the local speed shop it an "economy" model - for saving gas. I MIGHT be getting 8 mpg if I'm lucky, but I have other issues that might be affecting that number too.

I think if you email Holley with your spec's and let them know where you want to go they'll tell you what carb you need.

[Earlsfat]

Oh yeah, I'm pretty sure it's the vaccuum secondaries that are limiting your upper RPM HP. From what I understand, the double pumper set-up really gets things flowing they way they should be, and as I was told "makes a world of difference".