Carburetor Question

Bayoulee

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Having a 440 built. Bored.30 Promax heads, mild Melling cam. Looking at carbs and wanted some expert advice. Here are the two i have been looking at:
Suggestions or other options? Thanks-

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If you are more into the carter style of carb, then you might take a look at the Edelbrock AVS2 It is a 800 cfm carb. Jeg's has then with more being produced this month to meet demand. reason I can say this is because I called the factory and asked last month.
 
If you are using your car for street use only and not for only racing applications or top speed runs, then the clear choice for me would be the HLYO-83670. Electric choke and non double pumper and 670 CFM that is about perfect for normal street use for a 440. Usually Holleys don't have bowl vents but if you live in a high temperature area that would be a nice feature to have. I am not sure whether the AVS 2 has them either, but that is also an excellent carburetor for normal street use.

If you don't mind weak low end performance and a significantly higher price you can go for an 850 CFM double pumper Holley and regret it for the rest of your life unless you make a lot of top speed runs on the Bonneville Salt Flats.

I worked in the fuel systems lab when employed by Chrysler for 9 of my 11 years with the Corporation in Highland Park, Michigan (Central Engineering Headquarters).

Most newbies are impressed by big numbers but you really need to understand the implications - larger numbers don't translate to better performance unless you are really a top speed racer.

Good luck.
 
The biggest question is what you have in mind for your ride. Cruising or drag use? This helps define which way to jump in picking a carburetor. Do you want one that is relatively simple to use and adjust, etc.? Define the parameters of what you want to do. It's easy to get into a "lively" discussion here between the virtues of holly style carbs and carter (Edelbrock) style carbs. Also Fuel Injection vs mechanical style.
 
If the Promax heads indicate street/strip, I'd go Holley 83770 770cfm. Vacuum secondary is more streetable, better gas mileage.
 
Holley 3310. 750 VS.
Avenger, you will have struggles getting to work properly.
Edelbrock- meh, should run well enough to move itself around
 
If you are using your car for street use only and not for only racing applications or top speed runs, then the clear choice for me would be the HLYO-83670. Electric choke and non double pumper and 670 CFM that is about perfect for normal street use for a 440. Usually Holleys don't have bowl vents but if you live in a high temperature area that would be a nice feature to have. I am not sure whether the AVS 2 has them either, but that is also an excellent carburetor for normal street use.

If you don't mind weak low end performance and a significantly higher price you can go for an 850 CFM double pumper Holley and regret it for the rest of your life unless you make a lot of top speed runs on the Bonneville Salt Flats.

I worked in the fuel systems lab when employed by Chrysler for 9 of my 11 years with the Corporation in Highland Park, Michigan (Central Engineering Headquarters).

Most newbies are impressed by big numbers but you really need to understand the implications - larger numbers don't translate to better performance unless you are really a top speed racer.

Good luck.
Thanks, definitely looking for nice street performance. Appreciate it
 
My builder also recommended the AVS in 800cfm. To clarify, its going to be a street rod cruiser not a dragster. Wanted it to run good on pump gas. If i go with the AVS, how does one know how a 670 would perform next to the 800?
 
My builder also recommended the AVS in 800cfm. To clarify, its going to be a street rod cruiser not a dragster. Wanted it to run good on pump gas. If i go with the AVS, how does one know how a 670 would perform next to the 800?

I have been assuming you have a pretty stock setup since you say "mild Melling cam", somewhat improved heads etc. but there are a wealth of other factors that come into play like the stall speed of your automatic transmission torque converter (most C bodies with a 440 HP engine have low stall converters from the factory for example), 3.2 rear axle ratio and on and on. Here is a thread from the For B Bodies Only site that is related to this C body forum that discusses some of the factors you need to consider and then decide what changes you can afford to undertake to improve the performance for your vehicle where you want it to perform the best.

Chrysler's best C body efforts yielded the 440-6 pack setup in the 1970 Plymouth Sport Fury C body models and you could duplicate that package for your car for around $3000 plus possible rear end ratio, torque converter stall speeds etc. changes. It all depends on how much money and effort you want to put into your car..........

Carb Size Street Car - Advantage of QF 780 cfm over 735 cfm?

For example, if fuel consumption and overall cost doesn't concern you much then the sky is the limit.

Like I said, I was assuming you wanted to keep things pretty simple, reasonable cost and minimum changes compared to the stock setup in your car as it currently is for the large part and running during more normal street conditions..........................

Here is a photo of that 440 6 pack setup in a Sport Fury GT:

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I also have that set up in my 1970 Cuda and although that car is some 600 - 800 lbs lighter than a C body, it does run excellent with its progressive throttle linkage and vacuum operated secondaries as shown in more detail above.

Cuda #3 (1) (1) (1) (1) (1) (1) (1) (2).jpg


Best wishes...............................
 
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I lied that cam above wasnt available. I ended up getting The Melling MTD-2 is a 1200-4700
 
Holley's are overpriced, Brawler (Holley copy) is more reasonable. Nothing less than 750 cfm unless you are a seriously slow driver.
A Eddy avs, or avs2 is a easily adjustable demand carburetor, adjust the spring tension tighter it slows down secondary opening eliminating bog and flat spots, allowing tailoring carb to engine capabilities.
 
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I used to have a street avenger 670cfm that I converted to annular boosters. Tuned it with a wideband gauge. Best my smallblock ever ran...best mileage I ever got. Very responsive. Comparing dogleg booster vs annular, I had to jet down 5 jet sizes to lean the afr back out, thats how good those atomize.

On second thought, look at quickfuel, they are pricey but very good carbs by the looks of it, dont 'cheap out' on the mixture factory!

I have now switched to efi and my mileage went down the drain, assuming because the efi system is like a double pumper opening all 4 barrels at the same time?
 
I lied that cam above wasnt available. I ended up getting The Melling MTD-2 is a 1200-4700

I came within a pubic hair of buying that cam for my own project! It's very good for low end stuff. You needn't trouble much over a big gulping carburetor with that cam either. Calculate the volume of air you will need at 4700 rpm if you will...... I chose Summit's SUM-6400 for this particular job, as it comes VERY close to the stock 1966 specs. This I want, using the 915 closed chamber heads. These RV cams do well with closed chamber heads in general, which are ideal for popping lots of torque at the bottom end of the revolutions, good idle vacuum and such. Keep us posted about that MTD-2, as I might yet want one for my 400.
 
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