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im stuck on which carb to get for my 400 sbc...i heard alot about double pumpers but i dont know much about speed demons..does anyone run a speed demon on there car and if they do can you let me know how it runs performance wise thanks
 

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I'll second Prosystems for the carb.
Perhaps the best money I spent was one of their carbs. A/F ratio was darn near perfect throughout the rpm range when dyno'd last summer.
Throttle response on his carbs is amazing.
 

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I used a 750 speed demon DP on my 406 and with minimal tuning it ran excellent. I could mat the throttle from idle and no hiccups. Carb had excellent throttle response.
 

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im stuck on which carb to get for my 400 sbc...i heard alot about double pumpers but i dont know much about speed demons..does anyone run a speed demon on there car and if they do can you let me know how it runs performance wise thanks
A Speed Demon is a double-pumper. It's Barry Grant's version of a Holley.

If you're not very experienced with carbs you might be better-off going with one from one of the many carb shops out there but they are not very difficult to tune and the new Demon models and Holley HPs and their other performance carbs come pretty-much right out of the box with all of the significant enhancements you would want. All that is usually required is a little fine-tuning.

The bottom line is that you can't go wrong with either a Holley or a Demon. They are basically the same animal and you won't see much difference in performance between similar models if they are both properly tuned.
 

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If your wanting a good street carburetor try the Holley 770 street avenger.

The speed demon is a good carb also but if you have limited experience with tuning carbs start out with a street avenger vacuum secondary carb.
 

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I've been through a couple Demons... Both full of casting trash. Besides having a FAT initial factory tune, good carbs.

The Holley's seem to be a little leaner out-of-the-box which is where most of their bad mouthing comes from (stumbles and hick-ups). Easy to tune but can get costly as well.:yes:

I too would recommend calling AED or Pro Systems. Then you dodge 99% of the potential problems and get an awesome carb in the process!!
 

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To many variables!
Need more info

You say 400sb
What has been done?
Transmission?
Converter
rear gear
Car weight

These factors have a direct effect on the result of the carb you choose.

In a nut shell.
Double Pumpers are for all out performance, if your application can handle this.
Holley's in 99.9% of the time are dead on.
This stumble and stuff people have or talk about is a result of the wrong carb for the application! To much carb for the application.

Barry Grants are for total performance, they will require tuning. This is what they are for. This is what the company is about. They do tend to be on the rich side.
That is better than the opposite of lean! If you don't know about calibration tuning stay away from a BG.

Everyone wants to be a Carburetor or cam shaft guru!
I have this, I have that!

Best result, post your specs. And maybe give some more direct suggestions.

Also call Holley tec lne. But have your info. All of it.

In Holley the Vacuum secondary carbs are the best for street use. The vacuum secondary carbs also react to improvements to vehicle and engine upgrades. The system is a on demand system. The engine controls the amount of CFM it wants with the Vac secondary system.

Good luck!
Al

Asking the question, I have a 400sb what carb?
???????????????????????????????????????

I need tires for my Chevy! What should I get?
liitle more info needed!:rolleyes:
 

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try the Holley 770 street avenger
I like that carb too. Also like the Street H.P. series; we bolted one on my 410 SBC in Dale's Dart and ran 11.47 at almost 120 m.p.h.--it's an out of the box 750 vacuum secondary with a jet change. We made 2 passes at an 1/8 mile track and ran 7.365 twice back to back.
 

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My redone CSU 850dp should be here soon and they are a great company for carbs and they make a 750 as well.
 
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