DUAL QUADS

I HAVE A 57 BUICK WITH A 364 . I ALSO HAVE A DUAL QUAD INTAKE BUT NEED CARBS WHAT SIZE, BRAND ETC.. DOES ANYONE HAVE ANY FOR SALE?

I have the 2 Carter AFB four barrels for a '65 SuperWildcat 425 nailhead (3925S and 3646S). They need rebuild but are all there...carb linkage, choke etc...I could not guess what mods would be needed for your application. The set is $645 + shipping.

The 401 intake is too wide for the 364. It will fit with some port work, but you would be better off finding a 364 intake

Joe, I do believe you are right, that the 364 is best off with it's own intake. Sounds like he already has a dual quad intake and wants carbs. My sentiment is the smaller the better. I know the 425 2x4's are a smaller (575 CFM) size. If the original poster is interested here are the specs for the AFB Series Carbs:

CFM Venturi Diameter Bore Diameter

primary secondary primary secondary

--------------------------------------------------------

400 1 1/8 1 1/4 1 7/16 1 7/16

500 1 3/16 1 1/4 1 7/16 1 11/16

575 1 1/4 1 9/16 1 9/16 1 11/16

625 1 3/16 1 9/16 1 7/16 1 11/16

750 1 7/16 1 9/16 1 11/16 1 11/16

The 400's would be best for the 364...I offer mine because they are a BUICK application, this may be of great value if the throttle linkage can be readily adapted to his car. I've attached a photo of an identical running setup(Click "ATTACHMENT" above)Steve

THANKS FOR THE INFO , BUT YOU MADE ME A BIT NERVOUS. THE INTAKE IS AN OFFENHAUSER THE ONLY NUMBER ON IT IS ON THE BOTTOM 3412 BUT I CAN'T FIND THERE WEB SITE. ANY IDEAS? I FOUND A PAIR OF CARTER AFB'S # 3922S , 3921S BUT DON'T KNOW WHAT SIZE THEY ARE. ANY HELP WOULD BE GREAT.

Offenhauser catalog lists manifold 3412 to fit 1953 - 1956 Buick. The Offenhauser manifold for 1957 -58 is listed as 3556. Offenhauser does not have an active website, but contact information is:

Offenhauser Sales Corporation

5300 Alhambra Avenue

Los Angeles, California, 90032

(323) 225-1307

Carter AFB 3921 and 3922 are single 4 applications (one A/T, the other S/T) see referenced website:

http://www.thecarburetorshop.com/Kbuick3.htm .

These would be a mismatch for any engine.

Jon.

Carter AFB #'s 3922S and 3921S are from the '65 401 and single carb 425. 3922S is for manual trans., and 3921S is auto, used on either engine in all bodies. I don't know the size/flow, but they are probably too big for your application. I believe the factory nailhead 2x4 set ups had front carbs with no choke and no idle circuits, might be what you want with a suitable progressive throttle linkage. '65 front carb was 3645S (manual and auto), rear was 3634S (manual), 3646S (auto). I would guess the difference in the rear carb is only in the throttle lever stud, auto would have stud for trans. kickdown switch? Sorry, I don't have info. on other years. Hope this helps.

{edit} The site Jon listed doesn't agree with my post Re:'65 2x4 REAR carb #'s

I used:

NHRA Tech Specs

You're on your own from here. Good Luck!

Dual Quad Carb #'s

1964

Primary...... (Rear) 3646S Carter AFB for Automatic Trans

....................3634S Carter AFB 4 Speed

Secondary(Frt).................. 3645S Carter AFB (both Trans)

1965

Primary...... 3925S Carter AFB for Auto

.....................3924S Carter AFB 4 Speed

Secondary ...................... 3645S (same as 1964)

This type setup (progressive linkage) is by far the best for street use in multiple carb setups. At idle and low throttle, primaries in rear carb are in use, much as a single 2bbl. At approx half throttle, primaries of secondary carb kick in. Secondaries of both kick in simultateously at WOT.Nothing beats the sound of 2 four barrels opening up in a downshifting Full-Size Buick. Nothing Mechanical, Anyway!

This (Part# info) from my own experience and can be verified in Buick Service Manuals.Will have to tell NHRA to get their shite together.

57Buick, sorry if I made you nervous...check my earlier post...I typed up a chart so you can figure the CFM of a Carter AFB for you...just measure the primary and secondary bores! Steve

Gungeey has it correct. I don't know where NHRA got their specs. Gungeey referenced the Buick manual; our information (The Carburetor Shop website) is from Carter factory specifications. Carter Form 5466 covers all Carter AFB's used on the 1964 Buick; Carter Form 5481 covers all Carter AFB's used on 1965 Buick.

I would also suggest that gungeey is correct in using progressive linkage IF the original carbs are used (MOO - they are too big for the street!). We have had many unhappy Buick owners turn into very happy Buick owners when the original dual quads were replaced with Carter 400 CFM (part number 9400-S); and hooked up as two "primary" carburetors (that is, the linkage is so fabricated such that both carbs work simultaneously with choke, and idle on both). 0-60 times were MUCH improved, as well as driveability. Cannot say for sure what 1/4 mile time would be, as none of these owners put the car on the drag strip; but the larger carbs would have to make up a bunch at the top end.

Jon.

I forgot to mention: a picture of an original set is on our website:

http://www.thecarburetorshop.com

Jon.

not to change the subject but

i would like to find a carter abf #3634s

if any one has one let me know

scott

pphil36155@aol.com