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Discussion Starter #1
I've been running the 750 cfm vac. secondary on my 351W w/ Edelbrock RPM heads, intake, Comp Cams 280H cam, headers, etc. I could not get rid of the off idle stumble with this setup by adjusting the carb. I even bought the tuning kit and changed metering rods, springs, etc. My best et. at the track was [email protected] mph with me babying it off the line to get by the stumble. I finally got fed up, called Edelbrock tech and they said the accelerator pump circut is too weak, wanted me to drill out the shooters to help get rid of the lean condition when I launch. I decided instead that I'm going to sell the carb on and switch to The Speed Demon, 750cfm, mech. secondary. I went to the track today after just literally bolting this new carb on and ran a 12.89, 12.93 and 12.91 right in a row, most consistent 3 runs I've ever done and absolutely NO stumble, bog or hesitiation. Anyone badmouthing the Demon carbs can try my Edelbrock. The throttle response is like night and day and my idle even smoothed out compared to the 1407. I'm overall very impressed and this is the best my car has ever run. I noticed my plugs were a little dark so after re-jetting I think it will do even better which is impressive for a 3500lb car.
 

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Welcome to the world of Demon carburetion.
I really like the demon's I have had a Road Demon on the 351C and I run a 750 speed demon vac secondaries on the 429.
I will look forward to see what you run when you get it tuned in!
 

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Hmmm, that is disappointing to hear as I have just purchased a 1411 (the electric choke version of the 1407). I have the RPM heads, RPM intake and RPM cam (still on back order, thank you, edelbrock).

What intake are you running?

I am very surprised that you are unhappy with the edelbrock because I asked the forum about the edelbrock before commiting to mine and the feedback was all positive.

I guess I will just have to see if the total RPM performer package has better response across the full range.
 

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From my experience with Edelbrock/Carter carbs, they are fine on stock to mild motors. Start adding some duration to the cam and forget about it! Its time to move onto a Holley based carb. The Edlebrock carbs just don't have the ability to adjust the accelerator pump circuit on a stout running motor.
 

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Discussion Starter #6
You may be okay with the RPM cam, I'm using the 280H which is taller and longer dur. on the intake side. For the racing I'm doing, the 1407 doesn't have enough accel. pump squirt to launch the car, on the street it wasn't too bad, but the Demon is definitely better.
 
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