625 or 750 for stock 340

[duster360]

I am going to pick up a carter Avs in case I should decide to go back to stock with my car in the years to come. I have the stock iron 340 intake but should I get the 625 cfm Avs or the Avs from a 440 which are 750 if my memory is right.

 

[duster360]

Just did a lot of search reading and decided the 625 would be best.

 

[UOP]

I agree

 

[69 Cuda 440]

I am going to pick up a carter Avs in case I should decide to go back to stock with my car in the years to come. I have the stock iron 340 intake but should I get the 625 cfm Avs or the Avs from a 440 which are 750 if my memory is right.

The Stock 340 Intake {1968 thru 1970} works best with the Carter 625 CFM AVS {1 7/16" Primary ~ 1 11/16" Secondary}

Especially with an Automatic Transmission

Carburetor List Numbers
1968 = #4424 {Manual} ~ #4425 {Automatic}
1969 = #4611 {Manual} ~ #4612 {Automatic}
1970 = #4933 {Manual} ~ #4934 {Automatic}

The 440 utilized a 750 CFM AVS {1 11/16" Primary ~ 1 11/16" Secondary}


#2531915 ~ 340 Manifold {1968 and 1969} = 1 7/16" Primary ~ 1 11/16" Secondary
#3418682 ~ 340 Manifold {1970} = 1 7/16" Primary ~ 1 11/16" Secondary

 

[Johnny Dart]

The 625 would be the better choice.
Keep in mind,parts for the early Carter's are getting harder and harder to find.

 

[duster360]

I wonder if I should just hold out until the day comes that I need it and just buy a new edelbrock thunder Avs. Sure would be nice to have an original one though.

 

[abodyjoe]

I am going to pick up a carter Avs in case I should decide to go back to stock with my car in the years to come. I have the stock iron 340 intake but should I get the 625 cfm Avs or the Avs from a 440 which are 750 if my memory is right.

wasn't a popular upgrade back in the day a 440 carb on the 340?

 

[RustyRatRod]

wasn't a popular upgrade back in the day a 440 carb on the 340?

Yup. Since the AVS is similar to the Thermoquad, they are more forgiving. Although they don't have the small primaries, the secondary air door is still tunable enough to allow them to be used on a wide array of engine sizes.

BUT.....I don't think they are a bolt on swap. I think the 440 carburetor has larger bores and requires a spacer. I could be mistaken, but I think that's right.

 

[duster360]

Yup. Since the AVS is similar to the Thermoquad, they are more forgiving. Although they don't have the small primaries, the secondary air door is still tunable enough to allow them to be used on a wide array of engine sizes.

BUT.....I don't think they are a bolt on swap. I think the 440 carburetor has larger bores and requires a spacer. I could be mistaken, but I think that's right.

Good info to think about.

 

[69 Cuda 440]

Correct,

A Carter AVS 750 CFM,

Will not bolt directly on a Stock 340 {1968 thru 1970} Intake.

It has 1 11/16" Primaries.

 

[GTS Registry]

I dealt with a Stock Eliminator carb builder who flow benched the AVS.....ready for the real numbers??

The stock 650 flowed closer to 450 cfm, and the stock 750 AVS flowed closer to 550 cfm.

 

[duster360]

I dealt with a Stock Eliminator carb builder who flow benched the AVS.....ready for the real numbers??

The stock 650 flowed closer to 450 cfm, and the stock 750 AVS flowed closer to 550 cfm.

Anyone else ever seen numbers like this?