4429S carb on my 70 Cuda

[WhiteGP]

I found a Carter 4429S on my new - old Cuda, Should be a 4737S ... The 4429 shows to be for a 68-69 440 so should be OK, as I mentioned earlier the car has a slight low speed surge which the factory manual address's at the start of the 4737 repair section as the low speed idle needles are out of balance. I ordered a set of new needles for a 4737 ( yea, cart before the horse ) and need to lookup if the same needle size, should be but?

My issue is, the factory needles seem to be in a recessed hole in the base, and seem to be STUCK, they wont budge. am I working wit the correct needles ( I'm really not a Carb guy ). The factory repair manual says to pop off the plastic caps to get to the needles, are these the caps above the two "holes" or are the plastic caps just missing.

Someone save me from myself !!!

Thanks

 

[pschlosser]

The (1968) 4429 is an earlier AVS 440 carburetor nearly identical in specifications to the (1970) correct 4737. The 4429 has a single air/fuel mixture screw in the middle. A cleaned and correctly functioning 4429 carburetor should work fine on your 1970 440 engine. But if the carb is dirty, or out of whack in some way, then your faced with two choices:

1. keep the wrong 4429 carburetor and make it work. You would then use 440 maintenance data from the Carter 4429 documentation and 1968 FSM. New carb parts would be for the 4429.
2. find the correct 4737 carburetor and make it work. You would use the 4737 maintenance data matching the model year of your car, such as the 1970 FSM.

The two lower holes, where idle mixture screws are found on later AVS carburetors, like the 4737, were set at the factory and not intended to be set in the field. But that doesn't stop people from buying the 1969 and later AVS Idle Mixture screws and installing them.

The step-up rods between these two models of Carter AVS may not be interchangeable. At least, according to the Carter part lists on these two carbs. They don't seem to share a single step-up metering rod, but this isn't conclusive. And if you lay the new and old metering rods next to each other, and they look identical, then they probably are.

The stuck step-up rod, if that is the rod that is stuck, is a brass rod stuck in a venturi jet, also made of brass. Presuming they are still stuck, I strongly suggest you don't give up on that and soak the areas best you can with penetrating oil and try again. Even soaking the whole carb in diesel fuel for a few days, out in the sun, could be enough to free things up to separate them. Once unstuck, those parts may clean right up.

 

[WhiteGP]

The (1968) 4429 is an earlier AVS 440 carburetor nearly identical in specifications to the (1970) correct 4737. The 4429 has a single air/fuel mixture screw in the middle. A cleaned and correctly functioning 4429 carburetor should work fine on your 1970 440 engine. But if the carb is dirty, or out of whack in some way, then your faced with two choices:

1. keep the wrong 4429 carburetor and make it work. You would then use 440 maintenance data from the Carter 4429 documentation and 1968 FSM. New carb parts would be for the 4429.
2. find the correct 4737 carburetor and make it work. You would use the 4737 maintenance data matching the model year of your car, such as the 1970 FSM.

The two lower holes, where idle mixture screws are found on later AVS carburetors, like the 4737, were set at the factory and not intended to be set in the field. But that doesn't stop people from buying the 1969 and later AVS Idle Mixture screws and installing them.

The step-up rods between these two models of Carter AVS may not be interchangeable. At least, according to the Carter part lists on these two carbs. They don't seem to share a single step-up metering rod, but this isn't conclusive. And if you lay the new and old metering rods next to each other, and they look identical, then they probably are.

The stuck step-up rod, if that is the rod that is stuck, is a brass rod stuck in a venturi jet, also made of brass. Presuming they are still stuck, I strongly suggest you don't give up on that and soak the areas best you can with penetrating oil and try again. Even soaking the whole carb in diesel fuel for a few days, out in the sun, could be enough to free things up to separate them. Once unstuck, those parts may clean right up.

Excellent Information !!!, Thank you so much and you have a good point about a dirty carb, This one as you can see in the pic needs a little TLC, I think I will pull it and give it a good cleaning

 

[Xcudame]

PB Blaster should be on everyone's shelf!

 

[WhiteGP]

PB Blaster should be on everyone's shelf!

Sho is, Amazing stuff

 

[WhiteGP]

Excellent Information !!!, Thank you so much and you have a good point about a dirty carb, This one as you can see in the pic needs a little TLC, I think I will pull it and give it a good cleaning

Excellent Information !!!, Thank you so much and you have a good point about a dirty carb, This one as you can see in the pic needs a little TLC, I think I will pull it and give it a good cleaning

Pulled the carb, much easier to work on and after putting PB Blaster down the low speed ports the needles FINALLY came out, The new needles I bought for the 4737S appear to be the same so waiting on a new carb gasket from Summit, Local stores don't have much of a 1970's parts inventory

 

[WhiteGP]

The (1968) 4429 is an earlier AVS 440 carburetor nearly identical in specifications to the (1970) correct 4737. The 4429 has a single air/fuel mixture screw in the middle. A cleaned and correctly functioning 4429 carburetor should work fine on your 1970 440 engine. But if the carb is dirty, or out of whack in some way, then your faced with two choices:

1. keep the wrong 4429 carburetor and make it work. You would then use 440 maintenance data from the Carter 4429 documentation and 1968 FSM. New carb parts would be for the 4429.
2. find the correct 4737 carburetor and make it work. You would use the 4737 maintenance data matching the model year of your car, such as the 1970 FSM.

The two lower holes, where idle mixture screws are found on later AVS carburetors, like the 4737, were set at the factory and not intended to be set in the field. But that doesn't stop people from buying the 1969 and later AVS Idle Mixture screws and installing them.

The step-up rods between these two models of Carter AVS may not be interchangeable. At least, according to the Carter part lists on these two carbs. They don't seem to share a single step-up metering rod, but this isn't conclusive. And if you lay the new and old metering rods next to each other, and they look identical, then they probably are.

The stuck step-up rod, if that is the rod that is stuck, is a brass rod stuck in a venturi jet, also made of brass. Presuming they are still stuck, I strongly suggest you don't give up on that and soak the areas best you can with penetrating oil and try again. Even soaking the whole carb in diesel fuel for a few days, out in the sun, could be enough to free things up to separate them. Once unstuck, those parts may clean right up.

Thanks pschlosser, after spending 2 days working on the new low idle speed needles, I Finally got a good ( as good as I can I think ) dial-in and the car ran amazing today, idled well and low speed was much much smoother so were on to something. I still think the carb should be rebuilt and I should use it per your suggestion and per rarity of the 4737s so I ordered an AVS2-1905 to have as a backup / temp replacement when I get that done. Thanks again for the help !!!

 

[WhiteGP]

Thanks pschlosser, after spending 2 days working on the new low idle speed needles, I Finally got a good ( as good as I can I think ) dial-in and the car ran amazing today, idled well and low speed was much much smoother so were on to something. I still think the carb should be rebuilt and I should use it per your suggestion and per rarity of the 4737s so I ordered an AVS2-1905 to have as a backup / temp replacement when I get that done. Thanks again for the help !!!

I should add, I have a new set of wires, plugs, cap and rotor to install so looking forward seeing what that adds to the equation

 

[Ricks72Chlgr440]

Thanks pschlosser, after spending 2 days working on the new low idle speed needles, I Finally got a good ( as good as I can I think ) dial-in and the car ran amazing today, idled well and low speed was much much smoother so were on to something. I still think the carb should be rebuilt and I should use it per your suggestion and per rarity of the 4737s so I ordered an AVS2-1905 to have as a backup / temp replacement when I get that done. Thanks again for the help !!!

The AVS2 is a 650 CFM carb that uses annular primary boosters. Those boosters will give you superior off-idle response compared to other carbs. It is a bit smaller than the OE carb, but you probably won't notice the difference. I switched from a Quickfuel 780 VS carb to an AVS2 650 and was very surprised at the responsiveness. I bought the tuning kit and made some jet/rod/spring changes to zero in on the tune. There is absolutely nothing wrong with cleaning up your OE style carb, but the AVS2 would be an excellent replacement for it.

 

[WhiteGP]

The AVS2 is a 650 CFM carb that uses annular primary boosters. Those boosters will give you superior off-idle response compared to other carbs. It is a bit smaller than the OE carb, but you probably won't notice the difference. I switched from a Quickfuel 780 VS carb to an AVS2 650 and was very surprised at the responsiveness. I bought the tuning kit and made some jet/rod/spring changes to zero in on the tune. There is absolutely nothing wrong with cleaning up your OE style carb, but the AVS2 would be an excellent replacement for it.

Thanks Rick ! Great to hear this, I dont get into the peddle much ( Like in my younger days ) so yea looking for the a smooth "Cruising" experience, I will look at the tuning kit, good to know. I WILL say that when you do get into the peddle you KNOW there is a 440 on the other end ( pisses off the neighbors but brings a smile to my face )

 

[Ricks72Chlgr440]

Thanks Rick ! Great to hear this, I dont get into the peddle much ( Like in my younger days ) so yea looking for the a smooth "Cruising" experience, I will look at the tuning kit, good to know. I WILL say that when you do get into the peddle you KNOW there is a 440 on the other end ( pisses off the neighbors but brings a smile to my face )

Our 440's seem to make effortless power! Happy motoring!!

 

[WhiteGP]

Thanks pschlosser, after spending 2 days working on the new low idle speed needles, I Finally got a good ( as good as I can I think ) dial-in and the car ran amazing today, idled well and low speed was much much smoother so were on to something. I still think the carb should be rebuilt and I should use it per your suggestion and per rarity of the 4737s so I ordered an AVS2-1905 to have as a backup / temp replacement when I get that done. Thanks again for

 

[WhiteGP]

I got the AVS2 in, have been working on changing Plugs / Wires / Cap Rotor and adding MOPAR Performance valve covers ( they look good ) That DAMN # 6 plug is really pissing me off, impossible to get to without a lift or small hands. ( I was A LOT thinner last time I changed plugs in my V code ) I think I figured out why the 4429 carb is on the car, after crawling under engine #s dont match, I think I have a 68 or 69 - 440 375 HP, darn... everything matches but the 440, but still I have a super clean 70 U Code which make me very happy

 

[Xcudame]

With stock exhaust manifolds on big blocks, I've had best luck changing them from underneath the car. Plus the cool concrete helps here in the desert!

 

[WhiteGP]

With stock exhaust manifolds on big blocks, I've had best luck changing them from underneath the car. Plus the cool concrete helps here in the desert!

Thanks, I was just thinking about that a bit ago, I'll give it a go. Yea its been HOT here in Arkansas but not like out west ! I remember the first time i went to Mesa, wow.

 

[WhiteGP]

Thanks, I was just thinking about that a bit ago, I'll give it a go. Yea its been HOT here in Arkansas but not like out west ! I remember the first time i went to Mesa, wow.

Underneath the car is the ONLY way to get to that plug ! Thanks

 

[Kudakidd]

I was able to change all 8 plugs on my 440 from above. But it requires a LOT of patience! And as a side note, the diff between your carb and the 4737S is 100 cfm (750).

 

[WhiteGP]

I was able to change all 8 plugs on my 440 from above. But it requires a LOT of patience! And as a side note, the diff between your carb and the 4737S is 100 cfm (750).

You have a LOT more patience than I do, Thanks Kudakidd Yea the AVS2 is 650 cfm, maybe could have gotten the 800 cfm but it was on sale at Summit. I have plans to rebuild the 4429 in the future and put back on the car.