not sure if I can do this but here the link I use to find the 4121s
Pimary 1 1/16
Secondary 1 1/4
http://www.carburetor-parts.com/Carter-AFB_ep_277.html
273 carb choice
- Thread starter jh66cuda
- Start date
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not sure if I can do this but here the link I use to find the 4121s
Pimary 1 1/16
Secondary 1 1/4
http://www.carburetor-parts.com/Carter-AFB_ep_277.html
it does pull pertty strong but yea i would agree just because I didn't see it for myself..
Thanks, It is a old school grind but back in the day everybody made HP and torque with duration and not lift. The best thing about that concept is that you don't need anything fancy for valve train parts. Max HP compared to todays grinds? Nope, but a cool sounding street friendly grind that had enough power to smoke the tires. Yep! Like the old "Purple Shaft" cams from Ma Mopar. tmm
2 Darts
A-body Addicted
The carb was installed in my '66 Dart GT, 273 4v. It read 3855S. I assumed, silly me, that all 66s 273 4v used this carburetor when I answered the OP. This car was an extremely early (5 weeks prior to sale release date) '66 model. It had the Clean Air Package, though the car was originally sold in New Braunfels, TX.
The data I have from Carter regarding cfm and diameters is as follows (Pri/Sec):
500 cfm Venturi 1-3/16" / 1-1/4" Bore 1-7/16" / 1-11/16"
625 cfm Venturi 1-3/16" / 1-9/16" Bore 1-7/16" / 1-11/16"
In digging in the book that I got the above data from, I see that the 3855S is the same carburetor used on a 65 383 4v MT. Hope this clarifies my earlier post.
Mr 2 Darts,
I know, but the information listed on the Carter AFB 'internet site' is incorrect.
The following information is direct from the Carter Technical Specification pamphlet
that I received back in 1969 from the Carter Carburetor representative at the
NHRA Indy Nationals.
These CFM Ratings were called 'Factory Advertised'
--------------------------------------------------------------------------------
Carter AFB (500 CFM)
Primary....... 1 7/16" (1.063" Venturi)
Secondary... 1 9/16" (1.250" Venturi)
1965, 1966 and 1967..... '273 Commando' is rated at {500 CFM}
Note; Depending on who you talked to at Carter, this Carburetor
was rated between 517 and 525 CFM's.
-------------------------------------------------------------------------------
The Carter AFB for the Mopar (1963 thru 1967) 383 Engines and (1964-1965) 426
Street Wedge's.
Carter AFB (575 CFM)
Primary.........1 7/16" (1.186" Venturi)
Secondary.... 1 9/16" (1.313" Venturi)
or
Carter AFB (575 AFB)
Primary....... 1 7/16" (1.063" Venturi)
Secondary...1 9/16" (1.563" Venturi)
-----------------------------------------------------------------------------
Carter AFB (600 CFM)
Primary...... 1 7/16" (1.186" Venturi)
Secondary.. 1 11/16" (1.563" Venturi)
Note; This Carter AFB was used on the 1962 '413 Super Stock and 413 Ramcharger', and
1963 '426 Super Stock and 426 Ramcharger' {Stage 1} Engines.
Note; The 600 CFM rating was 'accurate'. Factory calibrated with smaller 'secondary jets' for the Dual-Carb set-up.
------------------------------------------------------------------------------
The Carter AFB (625 CFM) was found on the 1963 thru 1965 Chevy Corvette 327/300HP Engine,
and some Buick and Pontiac Engines.
Carter AFB (625 CFM)
Primary....... 1 9/16" (1.562" Venturi)
Secondary.. 1 11/16" (1.686" Venturi)
Note; The Carter Tech's labeled this the 'Killer Corvette Carb'. The rating was closer to 650+ CFM's.
--------------------------------------------------------------------------------
Carter AFB (750 CFM)
Primary....... 1 11/16" (1.463" Venturi)
Secondary... 1 11/16" (1.563" Venturi)
Note; Found on the later 1963 '426 Super Stock and 426 Ramcharger' {Stage II} engines and
1964 426 Max-Wedge [Stage III} engines.
Note; Also, 1967 440 HP 'Super Commando'.
I know, but the information listed on the Carter AFB 'internet site' is incorrect.
The following information is direct from the Carter Technical Specification pamphlet
that I received back in 1969 from the Carter Carburetor representative at the
NHRA Indy Nationals.
These CFM Ratings were called 'Factory Advertised'
--------------------------------------------------------------------------------
Carter AFB (500 CFM)
Primary....... 1 7/16" (1.063" Venturi)
Secondary... 1 9/16" (1.250" Venturi)
1965, 1966 and 1967..... '273 Commando' is rated at {500 CFM}
Note; Depending on who you talked to at Carter, this Carburetor
was rated between 517 and 525 CFM's.
-------------------------------------------------------------------------------
The Carter AFB for the Mopar (1963 thru 1967) 383 Engines and (1964-1965) 426
Street Wedge's.
Carter AFB (575 CFM)
Primary.........1 7/16" (1.186" Venturi)
Secondary.... 1 9/16" (1.313" Venturi)
or
Carter AFB (575 AFB)
Primary....... 1 7/16" (1.063" Venturi)
Secondary...1 9/16" (1.563" Venturi)
-----------------------------------------------------------------------------
Carter AFB (600 CFM)
Primary...... 1 7/16" (1.186" Venturi)
Secondary.. 1 11/16" (1.563" Venturi)
Note; This Carter AFB was used on the 1962 '413 Super Stock and 413 Ramcharger', and
1963 '426 Super Stock and 426 Ramcharger' {Stage 1} Engines.
Note; The 600 CFM rating was 'accurate'. Factory calibrated with smaller 'secondary jets' for the Dual-Carb set-up.
------------------------------------------------------------------------------
The Carter AFB (625 CFM) was found on the 1963 thru 1965 Chevy Corvette 327/300HP Engine,
and some Buick and Pontiac Engines.
Carter AFB (625 CFM)
Primary....... 1 9/16" (1.562" Venturi)
Secondary.. 1 11/16" (1.686" Venturi)
Note; The Carter Tech's labeled this the 'Killer Corvette Carb'. The rating was closer to 650+ CFM's.
--------------------------------------------------------------------------------
Carter AFB (750 CFM)
Primary....... 1 11/16" (1.463" Venturi)
Secondary... 1 11/16" (1.563" Venturi)
Note; Found on the later 1963 '426 Super Stock and 426 Ramcharger' {Stage II} engines and
1964 426 Max-Wedge [Stage III} engines.
Note; Also, 1967 440 HP 'Super Commando'.
Mr. 2 Darts,,,,
Carter #3855S and #3856S
Were utilized for the 1965 '383/315 HP' Big-Body Chrysler and Dodge cars.
They were rated at 575 CFM's
Carter {575 CFM}
Primary........ 1 7/16" (1.186" Venturi}
Secondary.... 1 9/16" {1.313" Venturi}
These Carter AFB's will work very well on a 273 Commando, even for a bolt-on upgrade on a stock 273.
Carter #3855S and #3856S
Were utilized for the 1965 '383/315 HP' Big-Body Chrysler and Dodge cars.
They were rated at 575 CFM's
Carter {575 CFM}
Primary........ 1 7/16" (1.186" Venturi}
Secondary.... 1 9/16" {1.313" Venturi}
These Carter AFB's will work very well on a 273 Commando, even for a bolt-on upgrade on a stock 273.
2 Darts
A-body Addicted
Mr. 69 Cuda 440,
I'm not here to debate. You win. :notworth:
My data came from Carter Carburetors 1988 ed. , by Dave Edmunds.
Given my experience with the 9635 I'm using on my 318, I stand by my comments to the OP.
In general, the smaller carb (500 - 550 cfm) will yield better throttle response. A larger carb will produce better top end at the expense of low end bog. For a street ride, I'd go with something in the 600 to 650 cfm range using a vacuum operated secondary (like the Carter/Eddie carbs discussed above). IMHO avoid mechanical secondary carbs on a street driven, small displacement engine (like the 273 & 318 ) with an automatic transmission.
It may be worth noting that the 318 cop car engine used a Rochester Quadrajet on it. The smallest Quadrajet is rated at 750 cfm. My Demon uses a Carter Competition Series AFB 9635 with a mild cam. Throttle response is very good. These combinations work because they have vacuum operated secondaries.
I'm not here to debate. You win. :notworth:
My data came from Carter Carburetors 1988 ed. , by Dave Edmunds.
Given my experience with the 9635 I'm using on my 318, I stand by my comments to the OP.
In general, the smaller carb (500 - 550 cfm) will yield better throttle response. A larger carb will produce better top end at the expense of low end bog. For a street ride, I'd go with something in the 600 to 650 cfm range using a vacuum operated secondary (like the Carter/Eddie carbs discussed above). IMHO avoid mechanical secondary carbs on a street driven, small displacement engine (like the 273 & 318 ) with an automatic transmission.
It may be worth noting that the 318 cop car engine used a Rochester Quadrajet on it. The smallest Quadrajet is rated at 750 cfm. My Demon uses a Carter Competition Series AFB 9635 with a mild cam. Throttle response is very good. These combinations work because they have vacuum operated secondaries.
Yes,
The Carter #9635 AFB is a 'very good' Carburetor choice for a 'Street/Strip Performance' small block Mopar,
'Advertised' CFM Rating = 625
Primary........ 1 7/16" (1.186" Venturi)..........(.098" Jet Size)
Secondary.... 1 1 11/16" (1.562" Venturi)......(.095" Jet Size)
The Carter #9635 AFB is a 'very good' Carburetor choice for a 'Street/Strip Performance' small block Mopar,
'Advertised' CFM Rating = 625
Primary........ 1 7/16" (1.186" Venturi)..........(.098" Jet Size)
Secondary.... 1 1 11/16" (1.562" Venturi)......(.095" Jet Size)
chloros340
Active Member
check out the 625 street demon. I put one on my 340 and was verry surprised with it.
http://www.demoncarbs.com/Types/Street Demon.asp
http://www.demoncarbs.com/Types/Street Demon.asp
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