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Old 05-16-18, 12:22AM   #1
Stubborn old goat
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Location: Pittsfield NH
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Default Square-bore carbs 3.75x3.875

Looking to rebuild 2 same model # cores that will bolt directly to my Offy 5499 DQ manifold without an adaptor, must have above bolt pattern dimension. I read this is the original 4 barrel pattern from the 50's. Source lists these as indicated below, there may be others with this pattern, am interested in them as well .. especially if 2 are available with same model #s.

Carter WFCB early
Holley 2140
Rochester 4G series
Stromberg 4A

I have 2 4360's which take an adaptor to mount to intake, may interfere with hood clearance and not have performance potential I desire. Would like to try both setups for hood clearance and performance and choose what works for me best.

I like Quadrajets alot and would enjoy expanding my Rochester skills rebuilding 2 4Gs. If they fit properly they might be my best no adaptor setup. Did just get a Carter book, like my Roe/Fisher Rochester book better tho.
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Old 05-16-18, 01:50AM   #2
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Sorry canít help you
The things they hide, the way they spin things, the excuses that they make and the things they omit.
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Old 05-16-18, 02:26AM   #3
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Did you ever work 4bbl carbs with that flange size and note results? I have not, only q-jets and Holley's 4150/60's with larger bolt pattern. Not sure there was an AFB that size ... Carter started with WCFB went to AFB then to AVS then Edelbrock(AVS) ... not sure Ive ever seen a Rochester 4G it was before Q-jet, am not sure that equals a Rochester 4-Jet which I just found several of on E-bay in my price range. I will most likely start with 4360's. Never seen a Holley 2140 or Stromberg 4A although I have no aversion to trying them if I can get a pair that will fit with no adaptor.
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Old 05-18-18, 12:13PM   #4
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Keith,ALL pre 67 pontiac 4 bbl carbs used the Carter AFB 4bbl carbs.I believe pre 1958 used the Rochester 4 bbls.The 60s AFBs are considered a square bore carb as compared to the Holleys which are a wide bolt spacing square bore.Offy makes the correct adapter that bolts to the Offy intake.I believe they actually made a adapter that had both the AFB and Holley bolt patter just like MANY square bore carb gaskets have.Tom
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Old 05-19-18, 07:55PM   #5
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Thanks Tom, spoke with a fellow close to you in Monrovia, Paul at Paul's Carb shop. He was referred to me by the Offenhauser tech rep. A Pontiac guy too as he has a 66 GTO fully restored in his shop now. He said he had a 5499 Offenhauser dq manifold like mine in front of him and 2 small bolt pattern Stromberg 4A's that would bolt to it without an adaptor bolt-hole wise BUT ... the throttle shaft actuating arms hit top of manifold runners on the lower front carb. I had seen this, even with the adaptors I have for my 4360's that raise carb about .750" the front throttle arm hits .. was just figuring I needed thick gaskets. Just discovered the gaskets in my Offy kits don't appear to be right ... they look relatively simple to make, will just cut my own, was going to trim adaptors as well as they have excess material overhanging carb flange. Trials and tribulations Guess this manifold never worked without an adaptor with any carb, front carb anyways ??
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Old Yesterday, 12:43AM   #6
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Best Holley for a Dual quad application is the 4224 center squirter the 4224 square bore 660cfm center squirter with the accelerator pump shot coming out of center of the carb hence the name center squirter. They use the 4150 bolt pattern.
All 4 butterfly's work at the same time opening and closing at same rate.
They also don't have a Power valve to worry about and there is a kit to add four corner jetting available for them and the side hung float bowls can be replaced with center hung float bowels. Makes tuning them a breaze if they are mounted side ways on a manifold. Jet changes are simple and quick.
Very versatile carburetor very tune able if you know what your doing.
I still have a nice set stashed away some where ?

They also made a 780 cfm carb of the same design I dont remember the List number. They are very rare but do pop up occasionally. I have no idea if they may be still available?
Dennis B.
A&P mechanic
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