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doing alot of reseach, this might help the new carb purchaser out.

benno440

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Supposedly with your 4150 carbs an 850 is the biggest size anyone makes blah blah, have a read then go do some research.

"I've been running a holley 850 dp for years, and decided to try a Proform 950 main body. I bought one and after examination noticed the venturis were 1/8" smaller in diameter than my 850. 1/8" X 4 venturis, thats almost 1/2" smaller overall!! This is the same size as the 750 carb!! I called Proform, the guy told me through angles and port work and shaping and blah blah they are able to get 950cfm out of it. I installed it on my engine, it has increased throttle response as expected, and a little pop or backfire when i first start it, sometimes. Now I see Proform has a 1050 main body, I called them today to get the venturi spec, and it is 1.56", the exact same as my holley 850. The 850, 950, and 1050 all take the same base plate. The truth is, Holley, Proform, or anyone else, do not make anything bigger than an 850. Even Holleys 1000 cfm is an 850 body, so is Quickfuel's and Proform's 1050. The higher cfm ratings are determined at different levels of vaccuum readings, etc. etc. to get what they need to make sales. Also, the Holley HP 950 uses the 850/950 base with a 750 main body, go to holley.com and check the specs, you'll be surprised this is true. The largest venturi size listed (other than dominator) is for the 850. Real world tests will show, I have my 1/4 mile times with the proform 950, I am going to put the 850 holley main body back on there and see which runs quicker, at the track on the same day. I believe this is a misrepresentation by these manufacturers, someone should do a flow test, keeping all factors equal on all the manufacturers carbs and report the findings. Its like flowing heads at 25" or 28", we should be told what conditions the carb is being flowed at also. Heck, if I can get enough people to send me their carbs I'll do the testing and send the carbs back!!"
 
Yes. just run an 850dp on the street. 1050 or 1150 dominator for anything 500+ cubes

all the other numbers are just sales hype
 
hmm im running 505 and going with a 850

will work well but a 1050 dominator will make more max power

I once put an ootb 1150 on a strong 440 in a 10 sec challenger (running 850dp) just to see what happens... it was just a little flat compared to the 850dp, but I was still very surprised how well it still went being only a 446ci
 
Then how come the an 850 cfm Holley pulls 2" of vacuum over a 1000 cfm 4150 Quickfuel on the same engine? My 850's and 1050's (both 4150) have completely different venturi designs.

What is the source of the original quote?
 
cant remember, i think a pontiac site, but i just googled 850 vs 950 carbs
 
the quote is a bit misleading.the main body and the base plate can effect the total cfm possible out of your carb.it dont matter if all the base plates are the same size,as long as it will flow the highest ratting.the overall cfm is controlled inside the flow of the main body.why else would aftermarket manufacturers list the same base plate for several diff size carbs?
 
I am just going from what i read on about 4 different sources that an 850 is the biggest carb you can buy, anything bigger uses a 850 base plate and the main body changes from there.
all 950's are 850 base plates with 750 main bodies supposedly.

correct me if i am wrong as i do not know much about any of this, and have only been reading this
 
if you look at a manufacturer like proform,just for example,they list the same billet base plate for 650 through 800 cfm carbs.the main bodys are individual for each size carb.i build franken carbs for my motors and have done tons of mods to holley carbs with great results. 10411292_237489503112653_6391885681296785854_n.jpg
current project has one on it.
 
I was told the same thing as when I was considering trying a 950 a few people told me the venturis are no bigger and even smaller then the 850 DP I run now. So I never did get the 950 as I also would like to borrow one and try it just to see how it does compared to my 850. Ron
 
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