Speed demon carb

muscle72

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Is a 850 speed demon good for a big block either a 383 or 440 with a 292 high extreme energy comp cam. Is the 850 to much carb? would a 750 speed demon be better?
 

Aron Gleason

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I would get a hold of Dominic thumper on Facebook. He's the go to carburetor guy. He's well known for how good his carburetors perform.
 

muscle72

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The shiny one? Not talkin about the one that's my profile pic.talkin about another l have
 
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beanhead

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What type of driving are you building for? Compression, heads/flow, intake, exhaust and engine size kinda need to be known for a real recommendation..
 

muscle72

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What type of driving are you building for? Compression, heads/flow, intake, exhaust and engine size kinda need to be known for a real recommendation..
Probably stock 906 heads with bigger intake and exhaust valves.either a 383 the cam is goin in or another 440 close to 10:1 compression or stock compression a 68 383 hp makes
 

BSB67

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Hard to pick a carb when you dont know the motor it is going on.
 

blue69runner

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650-700 cfm four barrel Holley is fine on a 383. 9.8 to 1 is what I am running. Plenty of pep. Running 80 jet's in it now it had 74 jetting on primary and 80 jetting metering plate. Changed to 80 jet's on primary and it work's fine now. Just my two cent's.
 

RJRENTON

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I would get a hold of Dominic thumper on Facebook. He's the go to carburetor guy. He's well known for how good his carburetors perform.

Who is "Dominic thumper" and what are his credentials. I'm a "carb guy" as well and I'm sure he's not heard of me either and I'm not on Facebook. Is he a self proclaimed expert too? Just curious....perhaps we can exchange some tuning "secrets".
BOB RENTON
 

Aron Gleason

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He doesn't claim to know everything, but he's well known. He's working with Shane Studley at precision cylinder head.
 

muscle72

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650-700 cfm four barrel Holley is fine on a 383. 9.8 to 1 is what I am running. Plenty of pep. Running 80 jet's in it now it had 74 jetting on primary and 80 jetting metering plate. Changed to 80 jet's on primary and it work's fine now. Just my two cent's.
What l thought for a 383 if l put a radical cam thinkin might have put a 750 on it. I have a 292 high extreme energy comp cam for it.im running a 600 Carter afb now on it.engine is stock basically with aluminum intake and headers.
 
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RemCharger

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Ever been on Moparts? He's well known there.
Who is "Dominic thumper" and what are his credentials. I'm a "carb guy" as well and I'm sure he's not heard of me either and I'm not on Facebook. Is he a self proclaimed expert too? Just curious....perhaps we can exchange some tuning "secrets".
BOB RENTON
 

PRHeads

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“Extreme Energy 292”??

There are:
292H
XE294H
XE295HL

I don’t know if the recommendations are still the same for the Speed Demon line since Holley took them over, but they used to be recommended for use with cams that were under 240@.040.

My experience with them has been that they were a little miserable down low when the duration started approaching that 240@.050 figure.
 

RJRENTON

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Ever been on Moparts? He's well known there.
What is he "well known there" for? I do not do facebook at all, or any of the "trendy" social media venues. I prefer to do my own do dilligance rather than taking someone elses opinion. I re-ask the question....who is "Dominic thumper" and what are his credentials? ....just because he has a face book listings does not qualify as an authoritative source. Nor do I know Shane Studley at Precision Cylinder Head.....does he own the business or just works there or does he design cylinder heads using computer modeling or ???? Perhaps, I could benefit from sharing knowledge....or not....
BOB RENTON
 

beanhead

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What is he "well known there" for? I do not do facebook at all, or any of the "trendy" social media venues. I prefer to do my own do dilligance rather than taking someone elses opinion. I re-ask the question....who is "Dominic thumper" and what are his credentials? ....just because he has a face book listings does not qualify as an authoritative source. Nor do I know Shane Studley at Precision Cylinder Head.....does he own the business or just works there or does he design cylinder heads using computer modeling or ???? Perhaps, I could benefit from sharing knowledge....or not....
BOB RENTON
Dom builds and preps carbs for mainly the race-oriented crowd, and while his business isn't necessarily to the level of notoriety of say Braswell, Dickey, Mike & Bo Laws....he has a solid customer following. Why he doesn't have a full-blown marketing campaign and fancy website, who knows...maybe he prefers word-of-mouth advertising and keeping a lower profile.
 

747mopar

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Just my personal opinion not knowing much about your build, 750. I've tinkered with an 870, 850 and 2 750's on my 456", all worked fine but driveability on the 850 & 870 for city driving just wasn't there. The 750 I have now is crisp everywhere under any situation.
 
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