intake mainfold

[dlcoop]

Looking for an intake manifold for my 425 nailhead.  I have a Rochester intake (66), but have a freshly rebuilt Carter.  I can return the Carter for a Rochester, but would prefer to use the Carter.  Must be reasonably priced or I will just get the Rochester. 

[BUICK RACER]

There are many on Ebay.

 

[dlcoop]

I am to the point I really dislike ebay.  I have filtered down on the search to 1964 fuel and delivery system and not one shows up. There is so much on ebay that I would never dream of putting on my car.  I really don't relish the thought of going through over 25k listed items and only 100 parts fit. Or parts listed as fitting a ford  but made for my buick.    UGH.

 

That's my rant for the day

[Loren@65GS.com]

I have an intake manifold off a ‘65 401. Should be same for the 425. Message me if you’re interested. 

 

Loren

[dlcoop]

Loren:  Is it for the Carter or the Rochester??   I have to make phone call first to the Carb guy and will see what he has to say also.

 

Dennis

[Loren@65GS.com]

It is for the Carter AFB.  The '65 Skylark Gran Sports used the Carter AFB carburetor as factory equipment. My Buick parts book shows the manifold for Carter carburetor as  P/N 1375548 for years '64 - '66.

 

 Loren 

[dlcoop]

I forgot my engine is a 66.  Has the quadrajet intake.  Csn you send me you price  and frt.    97760

[carbking]

Both the 1966 Rochester Q-Jet and the 1964~1966 Carter AFB's have both advantages, AND disadvantages.

 

Call if you wish to discuss.

 

573-392-7378 (9-4 Mon-Tues central time).

 

Jon.

[1965rivgs]

Buick installed the Rochester Quadrajet spreadbore carb and appropriate manifold on `66 425`s. The poster has the spreadbore manifold and wants to work out the carb for it.

Tom Mooney

[RivNut]

 I have an OEM 66 Q-jet, #7026240, from a 66 Riviera that I'd sell.  Send me a PM if you're interested. Probably needs to be gone through because it's been sitting for a while but Jon the CarbKing can provide a correct kit for you.

Here's a listing from Jon's website showing the correct carburetor number for a 1966 425 w/o A.I.R.  The 1777 is his kit number.

1966     8   425 W/O A.I.R.                    Rochester  QJET           7026240                   1777

Edited February 27, 2019 by RivNut (see edit history)

[dlcoop]

Thanks to all for the replies.  Have talked to my Carb guy and he has a Quadrajet he will exchange for me.  Again many thanks.  Everyone is a great help

[Loren@65GS.com]

4 hours ago, dlcoop said:

I forgot my engine is a 66.  Has the quadrajet intake.  Csn you send me you price  and frt.    97760

 

 The intake I have is for a Carter AFB. From your initial post, I understood it was an intake  you were looking for. Sorry for my misunderstanding.

 

  Loren

[RivNut]

6 hours ago, dlcoop said:

Thanks to all for the replies.  Have talked to my Carb guy and he has a Quadrajet he will exchange for me.  Again many thanks.  Everyone is a great help

Make sure it's for a 66 Buick Riviera.  The correct linkage on the carb is essential for proper operation of the kick down / switch pitch converter on the transmission.  The Buick Qjet for those years is very unique.  Fuel inlets, vacuum ports, etc. are all unique.  This was the first Year, Make, and Model for Buick to use the Quadrajet so it was a learning experience for them.  Lot's of things changed in each preceding year. 

[Pete Phillips]

I was not aware there were different intake manifolds for AFB versus Quadra-jet carbs, even if the engine is the same, but that's what I am learning from these posts. Learn something new everyday, I guess!

 

[dlcoop]

I guess we are never to old to learn something new.  I should have paid better attention. I have a 64 Wildcat but it has 66 heads on it.  (complete with the Calif smog ports).  I purchased a Carter AFB not thinking anything about it.  I have someone here on the forum  I am negoitiating to do a manifold swap. I have never been a real fan of the Quadrajet.

[RivNut]

This is a picture of a Quadrajet manifold. Different venturi sizes "spread bore" design, and the bolt holes are spaced father apart.

 

This is a picture of an intake for a Carter AFB (or a Rochester 4GC - both came as standard equipment) for a 401 / 425 Buick nailhead.  The 401 first became available in 1959 and ended in 1966.  Subtle differences from year to year.  This is called a "square bore" design.  The bolt holes are closer together.  

If you have a "spread bore" manifold and aren't interested in the additional CFM's provided by the Quadrajet, find a square bore manifold and sell the Q-jet manifold.  The "spread bore" manifolds are rare and desirable.  I got the pictures of these two off of eBay.  The asking price for the "spread bore" manifold is $699; the asking price for the "square bore" is $225. (Really high, you should be able to find one for $100 - $150.)  OEM Carter AFB carbs are rated at 625 CFM's; the Rochester Quadrajet is rated at 750 CFM's.  If you swap a later model Q-jet to your manifold, you can up the CFM's to 800+ .  The go fast guys love the larger carburetors.   

 

What ever you decide, make sure you match your carburetor (linkage specific) to the kickdown switch and transmission.   

Edited February 28, 2019 by RivNut (see edit history)

[RivNut]

Here's a picture of the bottom of a Q-jet.  Small primaries for economy and larger on secondaries that open based on air flow demand.

 

Here's a picture of a Carter AFB.  basically the same sized primaries and secondaries, and the secondaries are mechanical controlled by the linkage and your right foot.

 

 

No matter which way you decide to go, make sure that you put a stainless steel gasket between the fiber gasket and the base of the carburetor.  It's a heat shield that protects the aluminum base of the carburetors from the exhaust gasses that are passed along the base of the carburetor.  If you don't use a stainless gasket,  the exhaust gasses will corrode the aluminum carb base and the carb will be ruined

[Big Ricky]

It's tough to even find a carb to replace the original. Any suggestions from any of you?

[RivNut]

Big Ricky,

 

This post has been discussing both the square bolt (Carter AFB & Rochester 4GC) carburetors and the spread bore (Rochester Quadrajet) carburetor.   At this point it's hard to tell which is the"original" that you're looking for. 

 

Which is it?  You need to be very specific.

 

As I posted back in February, I have an original '66 Quadrajet that I'll sell. 

 

Ed

[Loren@65GS.com]

2 hours ago, RivNut said:

Big Ricky,

 

This post has been discussing both the square bolt (Carter AFB & Rochester 4GC) carburetors and the spread bore (Rochester Quadrajet) carburetor.   At this point it's hard to tell which is the"original" that you're looking for. 

 

Which is it?  You need to be very specific.

 

As I posted back in February, I have an original '66 Quadrajet that I'll sell. 

 

Ed

 

Ed,

 I must have missed that you had the carb for sale. I have an intake and have been watching for a carb. Sending a message.

 

 Loren

[RivNut]

Loren,

 

Sent you a PM

[Big Ricky]

Question:  Are there any other carbs that have the same linkage for the kick down/switch pitch converter?  Or are we left to only getting a rebuilt? Sorry, I missed your question. It's a 7020240 L 5   MA. 

Edited November 4, 2019 by Big Ricky
Adding clarification to question for Ed. (see edit history)

[RivNut]

Due to the fact that early production models will inherently have flaws, Rochester issued an updated replacement carb for the original sometime in the early 70s.  I do not know the number but I'm betting that some Google research would turn it up for you.

 

Ed  

[carbking]

7020240 does not exist.

7026240 was the 425 Federal carburetor in 1966.

 

7026240 was replaced by 7041304.

 

Good luck on finding one! You have a better chance of winning an argument with the IRS.

 

EDIT: (professional opinion). The BEST carburetor you can buy for a 1966 425 that is basically stock would be the 7041304. Second best would be the 7026240 after it was professionally rebuilt, and the early Rochester issues fixed (yes, there are issues, and yes, there are fixes). 

 

Other carbs could be used (various quadrajets, Carter TQ's, etc.) with the spread-bore manifold, but all would need some fabrication for linkage, fuel lines, possibly air cleaner adaptation, etc. Third choice would be an original Carter Riv AFB (not a new clone), with the square-bore intake.

 

The 7026240 CAN be made into an excellent carburetor, assuming the rebuilder does all of the machine work to plug in the "fixes".

 

As to new carbs, even if you found a new 7041304, it would require rebuilding, unless you have unlimited access to non-ethanol fuel.

 

Jon.

Edited November 4, 2019 by carbking (see edit history)

[Big Ricky]

Carbking,

Do you have any options in stock? Or maybe rebuild this one. It does look like somebody bolted up a couple spots that look "customized". I can load pictures up.

 

Thanks to all.

[RivNut]

There's a 7041304 for sale on Ebay right now.  $399. In your search just type in 'Rochester' and the carb number

 

[carbking]

34 minutes ago, RivNut said:

There's a 7041304 for sale on Ebay right now.  $399. In your search just type in 'Rochester' and the carb number

 

Nice looking core; but "NOS" with gasket residue on the throttle body???

 

Jon.

[RivNut]

1 minute ago, carbking said:

Nice looking core; but "NOS" with gasket residue on the throttle body???

 

Jon.

I made a mental note of the same thing, plus everything else looks like it has normal residue on it. 

[Big Ricky]

Thanks. Looking at it now. So this would have to be serviced I'm sure. Also, any thoughts on getting a Holley that fits and customizing the throttle linkage to reach to the kick down?

[carbking]

1 hour ago, Big Ricky said:

Thanks. Looking at it now. So this would have to be serviced I'm sure. Also, any thoughts on getting a Holley that fits and customizing the throttle linkage to reach to the kick down?

 

I would never have thought of it

 

If you have a boat load of Holley tuning parts, and own stock in Shell Oil, it is certainly an option.

 

Jon.

[RivNut]

1 hour ago, Big Ricky said:

Thanks. Looking at it now. So this would have to be serviced I'm sure. Also, any thoughts on getting a Holley that fits and customizing the throttle linkage to reach to the kick down?

Buicks run better on the OEM carburetor.  Lots more involved than just putting something on the manifold because the bolt patterns match.

 

In 1964, Buick built cars with 401s and 425s.  Both engines look identical unless you could compare pistons.  Both ran Carter AFB carburetors. Once again identical unless you could get inside and measure the jets and metering rods.  24 cubic inches called for different calibrations in the carburetor.  Holleys are generic and unless you have a bucket full of spare parts and are an expert at tuning carbs, you should stay away.  Run, don't walk.  Besides that, your air cleaner won't fit on a Holley or one of Edelbrocks cloned AFBs.

[Big Ricky]

Holley has the 0-80555C that matches the manifold bolts. Problem is the throttle linkage matching the kick down  position. Not unlike Dave's EFI custom linkage bracket. Do the Holley's mess with the fuel mileage? 

[Bloo]

Any universal aftermarket carb will need to be jetted and recalibrated to match your particular application.

 

Historically, Aftermarket Holleys have come out of the box jetted way too rich so they will run and drive on anything. Gas economy was typically horrible, and a lot of plug fouling followed. Most people don't understand that carburetors are not a universal bolt-on sort of thing, and that some development time and recalibration will need to follow. Can you imagine how many warranty claims they would have if they made a close guess, and on some of the cars they were too lean, backfiring, etc? Especially since almost everyone will buy a carb that is too big thinking it will make more power. I would be shocked if anything has changed. Too rich covers a million sins, but comes at a price. Aftermarket Carters for instance typically came out of the box a whole lot closer to where they needed to be, but they were also a bit rich, especially the "competition series". YMMV (literally).

Edited November 6, 2019 by Bloo (see edit history)

[RivNut]

2 hours ago, Big Ricky said:

Holley has the 0-80555C that matches the manifold bolts. Problem is the throttle linkage matching the kick down  position. Not unlike Dave's EFI custom linkage bracket. Do the Holley's mess with the fuel mileage? 

Have you yet explained exactly what you're trying to accomplish?  Do you just need a carb? Are you looking for performance? Are you looking for economy? (You can't have both).  Lots of advice but you seem to be reaching for something more.

[Big Ricky]

I'd like to restore but some performance would be nice. Not a show piece at this point. But my 204 carb has issues that a rebuild didn't fix. The wholes were plugged years ago, from what I can tell. I am definitely not anywhere near an expert. Just getting started and I am looking for options to get a good balance. Even considered EFI but not sure yet.  I was just curious what the Holley would do to it mechanically besides the throttle bracket customization. 

[carbking]

12 minutes ago, Big Ricky said:

I'd like to restore but some performance would be nice. Not a show piece at this point. But my 204 carb has issues that a rebuild didn't fix. The wholes were plugged years ago, from what I can tell. I am definitely not anywhere near an expert. Just getting started and I am looking for options to get a good balance. Even considered EFI but not sure yet.  I was just curious what the Holley would do to it mechanically besides the throttle bracket customization. 

The Holley8055C is significantly SMALLER than the 7041304.

 

Might be a good choice for a basically stock 350 Chevy.

 

If you got a Holley guru to totally recalibrate it for you, probably the only difference you would see just cruising would be a significant loss of fuel economy. Wide open throttle this Holley would lose a significant amount of power.

 

Best of both worlds. You can go slower, and do it by using more fuel  😜

 

Not many folks buy the Holley spread-bore carbs for performance.

 

Jon.

[RivNut]

Which holes were plugged and who rebuilt the carb?  Best balance IMHO would be the original carb off ebay IF it's truly in good shape. The next best would to buy a good core and have it professionally rebuilt.  The linkage to open the throttle blades is one thing, but the linkage to control the kick down and the variable pitch torque converter (two separate functions) is something totally unique to the OEM carb.  Anything performance wise that you might gain from a Holley will be lost without a properly functioning transmission.

 

Ed

[RivNut]

After reading Jon's last post. Scrap the Holley idea.  Find a good OE core and have it professionally rebuilt. Just don't "put a kit in it."  The value of an original carb will more than pay for itself if/when it comes time to resell. Less room for a prospective buyer to barter.

[Big Ricky]

Had, what I was told to be, a reputable re-builder here in NorCal to do the 240. (Carburetor Factory) Tough to know if they are that reputable. Maybe it just needs a good mechanic. I'm picking up the 304 on ebay to rebuild as well. I'll take some pictures of where I believe the holes have been plugged when I get back to the car. 

 

Just read your other post. I like that idea.

 

Edited November 6, 2019 by Big Ricky (see edit history)

[Big Ricky]

 

 

 

Here is the current 240 on my 66. Currently it gives me a strong hesitation as I hit the pedal from a stop or during a ride. From a stop it wants to stall, unless I tap the gas. If anybody has any idea why there's a hesitation as accelerating please let me know. Also, are there a reputable rebuild company out there?

 

 

 

Edited November 8, 2019 by Big Ricky (see edit history)