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Discussion Starter · #1 ·
just curious if anyone has tried this on a 6k max rpm big block? I ran an 830 years ago and it ran awesome and was super responsive on the street.


I'm gonna rebuild my stock 4781 holley and run it as is. if it would pick up strong midrange and make the car snappier than might be worth it.
 

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I am of the opinion (based on what guys in the know write about carb performance) that expert tuning of an existing carb gets you more bang for the buck than add on parts.

I experienced this when I upgraded my 427 BBC from an Edelbrock Air Gap and plain jane Summit 750 vac secondaries to a Weiand Track warrior 4500 base and an 850 Dominator carb without any specific tuning on the carb.

No measurable performance gain on the street or at the track. I guess that I shouldn't have been surprised and disappointed, but I was.
 

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just curious if anyone has tried this on a 6k max rpm big block? I ran an 830 years ago and it ran awesome and was super responsive on the street.


I'm gonna rebuild my stock 4781 holley and run it as is. if it would pick up strong midrange and make the car snappier than might be worth it.
I have a 750 mechanical secondary brawler with downleg boosters .
Awesome carb with all the versatility of much more expensive carbs .
I wanted to try anular boosters in that carb but there were only 2 options.
1) spend quite a bit of money to have my main body converted
Or 2) buy an anular booster body to use with my metering blocks

Holley/brawler did not offer an anular booster body for that carb at that time so I bought a proform body with anular boosters.
Huge difference in performance anular versus the down leg boosters.
Way more responsive and more torque.
That booster really atomizes fuel well .
I'm on the tail end of another SB build now and will be running anular on that as well .

. One issue can arise using these boosters though . There is such a thing as too much fuel atomization. If your running a "hot" intake , eg dual plane especially iron that tend to attomize fuel very well then you're running the risk of too much atomization if using anular boosters .
Single plane intakes run quite a bit cooler .

I was running an aluminum dual plane air gap that has long runners along with the anular boosters with no issue.
Id try anular on anything now
 
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I'd try this on that motor or a 4500 dominator
I'm tryin this one on a 385 sb with a weiand dual plane air gap


 
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just curious if anyone has tried this on a 6k max rpm big block? I ran an 830 years ago and it ran awesome and was super responsive on the street.


I'm gonna rebuild my stock 4781 holley and run it as is. if it would pick up strong midrange and make the car snappier than might be worth it.
On my 461 Peanut port engine this year my 1000 Down leg booster Demon was quicker and faster then my 850 Demon with A/D boosters so It may help and my not, the 850 has the same main body as the 1000. I think a lot has to do with what intake you are going to run.
 

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On my 461 Peanut port engine this year my 1000 Down leg booster Demon was quicker and faster then my 850 Demon with A/D boosters so It may help and my not, the 850 has the same main body as the 1000. I think a lot has to do with what intake you are going to run.
I saw/read somewhere that those Demon carbs won more races than all other carbs combined .
I had an oddball one that I bought new for a 350 6 or 7 years ago . It was a 720 with anular. I ended up selling it like the ignoramus that I was at the time all because some local yahoo who was workin on my shit couldn't get it to run because they are "junk "
Live n learn .

I'd go find another demon but I'm pretty carbed up and carbed out right about now lol
 

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You don't say what your doing? I don't see why anyone can comment.
 

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Discussion Starter · #8 ·
I was purely just curious. I have a mild performance 454. running a 750 dp and runs pretty good. picked up an 850 dp. was reading about the benefits on mostly lower rpm engines and some posts from david vizard and a couple of others on speed-talk. over the winter i plan on stepping up to a bigger hydraulic roller camshaft and a weiand stealth or air gap intake. the 4781 has the down leg boosters. opinions are all over the place. no one has actually run that particular main body that I know of. for $268 some first hand experience would be nice. otherwise that $ could be better spent towards the other stuff. if it would give a significant punch from 2k-6k rpm i'd probably roll the dice.
 

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I was purely just curious. I have a mild performance 454. running a 750 dp and runs pretty good. picked up an 850 dp. was reading about the benefits on mostly lower rpm engines and some posts from david vizard and a couple of others on speed-talk. over the winter i plan on stepping up to a bigger hydraulic roller camshaft and a weiand stealth or air gap intake. the 4781 has the down leg boosters. opinions are all over the place. no one has actually run that particular main body that I know of. for $268 some first hand experience would be nice. otherwise that $ could be better spent towards the other stuff. if it would give a significant punch from 2k-6k rpm i'd probably roll the dice.
I have run 2 big 4150 Mighty Demons on my BBC's. One is a 1000 and the other is the 850 with A/D booster. The down leg booster carb is quicker and faster on my BBC's but the 850 is better on my SBC's. Both have the same barrel openings. To make an 4781 flow like a 1000 cut off the air horn and re-couture the opening areas, add epoxy if needed. Next get the thin throttle shafts for your base plate and add the short screws to hold them in. Might cost you a few bucks but it will flow over 1000 cfm dry on the bench.
 
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