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I'm putting a 350 SBC in my Vega and I'm trying to determine what size carb to get. My motor is a 4 bolt crate motor, headers, Street performance intake, 270 comp Street cam. Other then that its pritty much stock. I was thinking a 650 Holley. Is that to big? What would you recommend?

Sorry I didn't know that there was a category for carbs and intakes.

A 650 sounds good for a street 350 engine.

There are so many variables to consider; not just engine size and cam, but lots of other factors. Auto or stick?, If auto, how loose a converter? Gears? Daily driver or only driven to the track?
If your Vega is automatic and fairly stock other than the mild 350, the 650 CFM reccomendation is pretty well right on. An Edelbrock will probably work pretty decent right out of the box and get you better mileage and drivability. If you have a manual trans and steep gears and don't care about fuel efficiency, you probably want a Holley double pumper. Most likely take some tuning to get it right, but the car will be quicker. Might even need a 750 if you rev it high enough.

spencerforhire wrote:There are so many variables to consider; not just engine size and cam, but lots of other factors. Auto or stick?, If auto, how loose a converter? Gears? Daily driver or only driven to the track?
If your Vega is automatic and fairly stock other than the mild 350, the 650 CFM reccomendation is pretty well right on. An Edelbrock will probably work pretty decent right out of the box and get you better mileage and drivability. If you have a manual trans and steep gears and don't care about fuel efficiency, you probably want a Holley double pumper. Most likely take some tuning to get it right, but the car will be quicker. Might even need a 750 if you rev it high enough.

Im going to look into the 650s and see what I can come up with.

I am running the Edelbrock 650 and have been very happy with it on my 350

A few google results. These should get you close. Just don't fall victim to the bigger is always better when it comes to carbs. My benchracing friend tried to talk me into a 1050 dominator. That is WAY too big for my mild pump gas 406. I run a Holley mechanical secondary 750 double pumper. It's set up for racing and not for street so i only get about 6mpg.

http://www.hotrod.com/how-to/engine/1408-how-big-a-carb-do-you-need/
http://www.summitracing.com/expertadviceandnews/calcsandtools/cfm-calculator
http://www.gtsparkplugs.com/CarbCFMCalc.html
http://www.4secondsflat.com/Carb_CFM_Calculator.html
http://www.pro-system.com/pjames011900.html
http://www.wallaceracing.com/intakecfm.php

It is actually pretty hard to over-carburate a drag race engine. They will often go quicker with a carb 10-20% too large. The engine can only take in what it needs; all that happens at WOT with a too-large carb is a drop in velocity as the vacuum reaches zero. My 383 which I consider "mild" as race engines go, works best with a 950cfm Holley HP. The math says I only need something like 910 CFM to feed the thing at 7800 RPM.

these guys have given good suggestions, on a mild smallblock I'd run something between 6 and 650 cfm, I'd shy away from going to a double pumper or going bigger unless its a race motor or it has high compression or something. I think right now the edelbrock on my mild smallblock is a 625, I'm not a huge fan of them but they're decent if you just want something to bolt on and not mess with. I think carb's are kind of application and people specific, depends on weather you like to tweak it fairly often or not. and it depends on what you want the vehicle to do.