After market replacement for 68 Carter AVS for 383 HP auto

[triple_green]

Tired of rebuilding this stock carb. I think it is a 4401s. I am told it is around 490-500 cfm. automatic trans.

What would be a good newer aftermarket replacement? I would be willing to go  up to 600 cfm or so if you think it is OK.

Thanks!

Mark

[ws23rt]

It's possible that something important was missed when your carb was "rebuilt".
Newer is not always better. 

[triple_green]

Rebuilt every 2-3 years since I owned the car. Last time 3 years ago. Always professionally.

Car is not driven much from Nov-April. Once a month or so. Started every two week or so during that time period.

thx!

[BSB67]

So exactly what goes bad every 2 or 3 years that a rebuild fixed that is unique to this carb?

[c00nhunterjoe]

So exactly what goes bad every 2 or 3 years that a rebuild fixed that is unique to this carb?

  im sitting here scratching my head asking the same question.

[myk]

What are the car's problem symptoms?  Carbs don't need to be rebuilt on a regular basis.  Honestly, I think driving a car irregularly causes more problems than anything else...

[triple_green]

OK this is good information.

The immediate, problem was a choke problem. (recurring). My mechanic is diagnosing now.(but he is the same guy who has fixed it the last 14 years) Also gas mileage just seems to keep getting worse. ( know that could be other things too).

Also I am wondering if there would be any noticeable performance gain by going to a slightly larger cfm carb.

everything else is stock except Pertronix elect ignition.

Thanks!

[John_Kunkel]

Don't know the cfm rating of the 4401 but it's gotta be close to 600 cfm.

[triple_green]

I have read it was only 490 cfm.

[fy469rtse]

Yep , edelbrock AVS ,
I'm assuming its a two barrel set up, on it now ,
you will need to get matching manifold , ie four barrel to notice any performance gain, yep go a 600cfm avs ,  spring loaded secondary door , its easier to adjust

[triple_green]

It is a stock 383 HP with the AVS 4 barrell.

[Al]

I run a Holley Street Avenger 670 cfm on my 383 and I am very happy with it. Needed some fine tuning though.
Al

[myk]

OK this is good information.

The immediate, problem was a choke problem. (recurring). My mechanic is diagnosing now.(but he is the same guy who has fixed it the last 14 years) Also gas mileage just seems to keep getting worse. ( know that could be other things too).

Also I am wondering if there would be any noticeable performance gain by going to a slightly larger cfm carb.

everything else is stock except Pertronix elect ignition.

Thanks!

So the choke isn't opening?  Or it won't close?  How's the driveability?  If your choke is stuck or won't open up all the way your gas mileage and performance will be affected quite a bit.  Yes, you can gain performance by going up in 'carb size, but unlike a woman's boobs, too big of a number can actually be a bad thing.  On a stock 440 like mine I wouldn't venture beyond 800 CFM; I imagine on a 383 it would be somewhat less...

[John_Kunkel]

I have read it was only 490 cfm.

Some of the Mopar AFB's that preceded the AVS were pretty small but no AVS flows that little.

As I've ranted many times before, there are no published flow ratings for OEM AVS's but most accurate estimates for the small 383 AVS put it at around around 600 cfm.

[BSB67]

Okay, so I've sat back and have taken in this discussion.  Let me start with my observations:

1) You are not really a wrench guy yourself
2) Not really interested in getting into the weed yourself on engine work and performance details
3) your tired of the car not running right,
4) you believe that it is not running right because of the carb
4) You want to make that problem go away
5) If a new carb is the solution, is there something that is a win-win for reliability and performance.
6) Once you install the new carb, You hope to never have a issue again.

Is this accurate? Because it effect the recommendations.

First, I really don't know why you are having a carb issue, and as mentioned, it could be the combination of it sitting a lot, and today's gasoline.  My first concern is that a carb change will not fix your issue.  My fist recommendation for you would be to fix correctly what you have.  If your mechanic cannot seem to do it, send it to someone that can.

If you are compelled to change the carb, and if my list above is generally accurate, I would suggest that you focus on reliability and idle through cruise quality.  I would let the performance part go.  You could probably get a few more hp out of what you got, but you would probably not even notice it.   Probably focus on something that is as close to direct replacement as possible.  Probably a Street Demon, Edelbrock AFB (Performer) or AVS (Thunder) in the 600 to 650 range.  There are Holleys that will work, but you will be cutting and hacking at your fuel line.

If it were me, I would try the Street Demon, just because it is new and seems pretty cool.  But I have no personal experience or even know someone that has tried it.  On paper it seem to have the potential to sharpen up your throttle response.  That will make you think it has more power, and make it more fun to drive.

[triple_green]

yes on all points.

I am not great mechanically.

Everything under the  hood is original or looks original except the "wear items". So the aftermarket car is going to look stupid. But I like to drive my car more than show it. The car does run well and has minimal problems. After this has happened 4 of the last six years I am just "sick off it". My mechanic doesn't seem to be able to make it go away. It only happens in short drive, sit for an hour and try to start again situations.

I was hoping for a little more power. The liability is good except for this one particular situation.

Yes I am a wimp....

Thanks for the good advice BSB67.

[BSB67]

yes on all points.

I am not great mechanically.

Everything under the  hood is original or looks original except the "wear items". So the aftermarket car is going to look stupid. But I like to drive my car more than show it. The car does run well and has minimal problems. After this has happened 4 of the last six years I am just "sick off it". My mechanic doesn't seem to be able to make it go away. It only happens in short drive, sit for an hour and try to start again situations.

I was hoping for a little more power. The liability is good except for this one particular situation.

Yes I am a wimp....

Thanks for the good advice BSB67.

It is irrelevant what your capabilities are, we just need to understand to respond accordingly.

[c00nhunterjoe]

My mechanic doesn't seem to be able to make it go away. It only happens in short drive, sit for an hour and try to start again situations..

You just described heat soak. A new carb wont fix that.

[Challenger340]

Maybe you can hold off a month or so ?
Too busy right now....
but come spring I will be putting a kit into my factory '69 AVS, because the accelerator pump is weak, and I will be putting it up on the new SuperFlow SF750 Flow Bench at the same time just for sh*ts & giggles.....
then we will know pretty quick what they Flow ? on what is considered a "state of the art" industry wide Flow Bench.

On another note, mine has had an under dash choke cable installed at some point in it's history ? Which, works absolutely flawlessly.
Pull the cable out while pumping the pedal 3-4 times cold, crank and start within about 5 revolutions, push the cable in just slightly and let it run on high idle until warm, push to cable all the way in, kick it down to idle, and away I go.
Subsequent starts throughout the day, even after sitting, just turn the key(no pedal).... and I swear here.... the thing don't spin 1/2 a crank and fires. Pretty amazing ! just fires right up everytime !
maybe you need a manual choke installed ?

If mine is any indication, and maybe it is just a "good one", but I am pretty darn impressed with the AVS carbs ?

[BSB67]

Subsequent starts throughout the day, even after sitting, just turn the key(no pedal).... and I swear here.... the thing don't spin 1/2 a crank and fires. Pretty amazing ! just fires right up everytime !
maybe you need a manual choke installed ?

If mine is any indication, and maybe it is just a "good one", but I am pretty darn impressed with the AVS carbs ?

It has been a while, but when I was using my factory AFB it was the same way.  Reach in through the driver window and turn the key.  As fast as you could snap the key to the start position, it would start.