which carb & cfm for a sbc 383 elco.

Old 11-22-2011, 08:18 PM
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loproelco
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Default which carb & cfm for a sbc 383 elco.

Hello all, Im a newbie to this forum and would like to ask a seasoned pro a question about carb's. I have a 67 el camino with all the following feartures, and would like your input on what size carb. My car weight is 3100lbs, sbc 383 scat rotation, flat top forged pistons mahle, summit aluminum heads 210cfm 64cc, fully solid roller valve train. cam specs are 256@ 50 lift is .600 staight across, a well built 350 tubo with a 3500 stall, 411 posi, 650 mighty demon dbl pumper on top of a hvh street sweeper spacer, and a brodix hv1016 dual plane intake , DUI hei and a electric fuel pump. The car runs pretty darn good. I just feel that there Is some performance left on the table. I would really value your opinion on the carb size here. The local track famoso raceway is closed til the 1st of the year, before I can run it on the track. Thanks, and sorry for the long-winded writing. Ty
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Old 11-22-2011, 09:25 PM
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maxpower671
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if you're looking for more perf, yes, try a bigger carb....like 750 holleys myself....never could get mileage out of them tho ops:
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Old 11-23-2011, 07:07 AM
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fast75vega
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Originally Posted by maxpower671
if you're looking for more perf, yes, try a bigger carb....like 750 holleys myself....never could get mileage out of them tho ops:
2nd that.... 750 double pumper :wink:
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Old 11-23-2011, 06:29 PM
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cncmotorsports
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The 650 might demon will flow the same as a 750, Barry grant underrated them 100 cfm. What was the compression ratio? If your not getting the performance change the cam and heads.
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Old 11-25-2011, 09:51 AM
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loproelco
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Default 650 mighty demon.

The compression is 11.25. I also heard that the BG carbs flow more than they advertised, but I don't know if that is really true. Thanks for the replies.
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Old 11-26-2011, 04:47 AM
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hammertime
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Most good aftermarket carbs flow more then your normal carb.

I also agree a 750 would be a upgrade. I'd go with something like this, there is a lot of gain to do something over a standard 750 holley/bg

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Old 11-27-2011, 06:50 PM
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maxpower671
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Originally Posted by hammertime
Most good aftermarket carbs flow more then your normal carb.

I also agree a 750 would be a upgrade. I'd go with something like this, there is a lot of gain to do something over a standard 750 holley/bg

what are the upgrades to that carb David? $Value? thanks!
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Old 01-12-2012, 08:10 PM
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bubbaf100
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I'd go for the money a Demon 750 Annular booster in the Mighty Demon.
If its for strip primarily it's the way to go. If want to buy the
Ultimate carb only on get the Race Demon RS can be from 575 to 1050 cfm.
Just change sleeves and base plate to your size if needed to change the baseplate at all. If you ever want to go big on another combo you
Already have the carb. 8)
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Old 01-13-2012, 02:05 AM
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JEFF69Z28
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CALL A CARB COMPANY APD,AED,PRO SYSTEMS, ETC,ETC, AND THEN YOU WILL KNOW EXACTLY WHAT YOU WILL NEED AND THE PRICE .
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Old 01-24-2012, 08:56 AM
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et7333
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I would use a 750 like mentioned.
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