Carb Suggestions

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KOZ45

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I am looking around for a new carb for my Duster with a 440

I would like to stick with a dual fed carb and redo the fuel plumbing that's on the carb currently

What CFM should I look for and what features are important. I believe I have a manual choke setup
20181227_084840.jpg


I will be installing an Edelbrock 1723 mechanical pump soon

I have a Wieand 7512 manifold, if that matters
 
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From the picture you have NO choke. If this is a street driven car with an auto trans I wouldn't go bigger than 850 and would suggest a 750 vacuum secondary. Also, under those same conditions the single plane manifold may not be your best choice.
 
Yes. Street driven with an auto

The Weiand too high of rpm performer?
 
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KOZ45 said:
Yes. Street driven with an auto

The Weiand too high of rpm performer?
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In most cases a single plane manifold doesn't work near as well as a dual plane on the street. Pretty much the RPM range usually won't match what you're running on the street. Not saying it won't work at all, but if you can swing it I'd go with an Eddy Air Gap or even a Performer dual plane.
 
Tell us about the engine. Everything you know.
What size carb is on there now? Cam specs would be very helpful. But if all you know is a part of grind number......

Generally speaking, a dual plane produces more low end torque. This will get you moving off the line quicker, street or strip. The RPM will also produce near equal hp to a single plane.

Carb wise, a 750cfm unit will provide enough. An electric choke is an excellent idea because it will give trouble free warm up, starting and driving.

You could put a vacuum gauge on it now and notice the vacuum level at high rpm. If it is greater than 1.5, a smaller carb can provide a few more top end hp. But it is a small gain. Sometimes the move to a larger carb will cause low speed driving problems. As well as a slight loss in throttle response. These issues maybe small but some people really want it “On the Money” and will go with a smaller carb.
 
I have no idea on the current carb, since there aren't many good marking in it and I bought the Duster with it as it sits

The motor I also am unsure , other than its a 1968 440 block with 906 heads and headers. The previous owner said the cam wasn't stock, but he also couldn't provide much info for me

The idea of replacing the intake manifold isn't out of my budget, and I would rather do it now along with a new carb
 
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I have been told by others that the current carb is a Holley 4150
 
I would go with :
Edelbrock RPM
Edelbrock 1812 Thunder Series AVS 800cfm manual choke.
.02
 
4150 is a style of carb, not the model #. Usually model # is stamped on the metering block just behind the float bowl.
 
I have a known good running Holley 3310 750 vacuum secondary carburetor. I loaned it to a friend to break his engine in. He used it, it ran good and he emptied it completely. I will take 175 dollars shipped to your door. It has a manual choke and works well. They are over 300 new. It ain't the shiniest thing in the world, but it's a good carburetor.
 
Measure the venturi bores and throttle plates. That'll help you determine what you've got now if the numbers aren't visible.
 
Not enough information given to help. All I've heard so far is 1968 440 with 906 years?? And a not stock cam? Help us help you
 
Dana said:
Not enough information given to help. All I've heard so far is 1968 440 with 906 years?? And a not stock cam? Help us help you
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Sorry, meant to type 906 heads and I don't have any more info on the motor
 
How much vacuum does the motor make? What is your rear gear?
 
Dana said:
How much vacuum does the motor make? What is your rear gear?
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Good questions

Rear end has the smaller 741 case with 3.23 gears, but when I bought the car I found a set of 4.30s under the seats. I will run the 3.23s for a little bit, but will eventually swap them out for something else, like the 4.30s

I need to do quite a bit of more work to the car, before it's running and I am able to get a vacuum reading
 
get it going first and see what's what. We're changing parts and giving parts suggestions and know NOTHING about the heads (are they ported? 2.08's?), nor of the cam (????), nor of the compression (what pistons???), nor the converter.

For what it's worth, my brother had a '68 GTX with a single plane intake. the M50's wouldn't hook, and it would fish tail at 50 mph down the highway when floored.

Again, get it going and see. Maybe just a carb kit and the carb will work perfect.

P.S. - My opinion, the cliché' "vacuum secondary for the street, double pumper for the track" line is hogwash
 
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318willrun said:
get it going first and see what's what. We're changing parts and giving parts suggestions and know NOTHING about the heads (are they ported? 2.08's?), nor of the cam (????), nor of the compression (what pistons???), nor the converter.

For what it's worth, my brother had a '68 GTX with a single plane intake. the M50's wouldn't hook, and it would fish tail at 50 mph down the highway when floored.

Again, get it going and see. Maybe just a carb kit and the carb will work perfect.

P.S. - My opinion, that "vacuum secondary for the street, double pumper for the track" line is hogwash
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^^^This^^^
 
I need to replace the carb, soon!!

I want to get a 750 cfm double feed/pumper, manual choke

Will any 750 work or do I need a 440 specific carb?
 
KOZ45 said:
I need to replace the carb, soon!!

I want to get a 750 cfm double feed/pumper, manual choke

Will any 750 work or do I need a 440 specific carb?
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Why do you want a choke?? They've never worked. Just order a ProForm 750 double pumper and be done with it.
 
I was told I need either a manual or electric choke, had to run one......no?
 
You still haven’t told us what I asked for, therefore;

Street, electric choke, it makes life easier.

Race, 750 no choke
 
KOZ45 said:
I was told I need either a manual or electric choke, had to run one......no?
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I have not used a choke since 1984. I don't do carbs with chokes since 1984. I drive my junk year around. I live in a high valley desert. I drive my car well below freezing. I've driven it in in single digit temps. No choke. And that's with a Strip Dominator intake. I've never, ever had a carb freeze like many claim.

I've never seen a choke do anything but make the oil dirty and wash down the cylinder walls. You don't need it. If you can't get the engine started and let it warm up for two minutes before you drive it, a choke won't help.
 
My experiences with 440s has always been, if they have been modified, they need more than a 750. Closer to stock? 750 is great once dialed in. Add headers, cam, intake?...a bigger carb, once properly setup will kick it's butt. Tuned right, they can have every bit the off-idle response but deliver more pull from the midrange on up. Be honest to yourself about your goals with it and go from there..
 
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