Originally posted by bobpar
I have a 355 chevy SB with a 270 INT./280 EXH. cam, Edelbrock Performer RPM intake, and headers. Some minor work has been done to the heads, but nothing to extensive. I have a Holley 600CFM marine carb. Could somebody tell me if this marine carb would work and if it would even flow enough CFM's. Or should I get a Edelbrock 750CFM, or would that flow to much air. Any help would be appriciated. Thanks, Bobby.
From what you wrote I would have to say that you are looking to overflow your mechanicals. You don't need a 750CFM anything unless you are going to beef up your motor later on.

Personally I'm in agreement with everyone else on the Marine carb. Ebay it. Get something useful out of it.

The Edelbrock you should shelve until you have your motor more beefed so it will run every bit of fuel the carb dumps into it.

Cause right now your motor will not burn that much fuel unless you've enlarged the Valves in your heads and added a beefier cam as well as increased your compression ratio.

It's just as bad to overfeed the motor as it is to starve it.

If you are running a stocker I wouldn't put much into it.

550cfm would be plenty.

If it's just a step up then...

600cfm

and work up 50cfm for each step of cam change that changes the duration.

Also Edelbrock is a decent Carb. There is noting wrong with it.

Unfortunately you can't tune the thing, like you can a Holley, Demon or Predator.

But you won't need any of these if you plan on running pump gas exclusively and if you want to keep your ride a dailey driver.

If you want to run the tracks more than the street I would suggest to use a squarebore carb for the street that you can yank and put on a tunable Holley DP. It's a decent carb, you can change the bowl size to accomodate the demand as well as change jet sizes to increase the flow rate.