# Carb Help



## [email protected] (May 30, 2021)

Hi men, first time, long time. I am in need of help trying to figure out what kind of carb I will need for my motor set up. Here's what I'm working with. 1967 400 bored out .60,068 ram air cam, MSD ready to run distributor, Offenhauser 360 single quad manifold. This car is a Sunday street driver. Thanks


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## [email protected] (May 30, 2021)

One more thing.1967,061 Heads


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## armyadarkness (Dec 7, 2020)

Holy can or worms, Batman.

The internet will tell you Holley, however...

Yes, Holley is great and highly tunable _IF _you know how. They're also (IMO) not user friendly. Jetting changes require bowl removal, which spills fuel all over the engine. depending on your model, fine tuning requires things to be drilled out. You will hear that Holley is made in the USA, that is not true. Holley is assembled in the USA, it is manufactured over sea's, like everything else. 

Do I love Holley? Yes, however their customer service is all but non existent. You can call 24/7 and sit on hold for hours. Their QC has also tanked. I just paid $750 for a Holley and it arrived bent and non functional, yet OBVIOUSLY packaged by Holley after the fact. So someoen dropped it, picked it up, shrink wrapped it, shot it with foam, and sent it to me. It took me two weeks to contact them and they we're completely unsympathetic to it all. I evaluate consumer products for the government, and even with all of my tricks and abilities, I've never reached a responsible party at Holley.

That being said, Quick Fuel and especially Proform, both make Holley carbs which are more user friendly and Proform has excellent customer service. So, they're the best of both worlds.

That being said, I have a 67 GTO (same setup) and I run an Edelbrock, AVS2 800cfm. The Edelbrocks are very easy to tune, without removing them from the car or draining fuel. Their customer service is readily available. They're much cheaper. They work easily "out of the box", and, their new annular boosters are a crazy great invention!

Plus, they're simply an updated Carter, which was an OEM carb for the 67.

You will also get many votes for the Rochester Quadrajet, but a reputable rebuild will be a minimum of $800. None of the Summit/ Amazon/ Ebay Qjets are endorsed by Lars or Cliff, for good reason.

And finally, for $1700, you ccan go Holley Sniper fuel injection, which includes a new fuel tank with all of the lines, filters, and pump.


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## PontiacJim (Dec 29, 2012)

[email protected] said:


> Hi men, first time, long time. I am in need of help trying to figure out what kind of carb I will need for my motor set up. Here's what I'm working with. 1967 400 bored out .60,068 ram air cam, MSD ready to run distributor, Offenhauser 360 single quad manifold. This car is a Sunday street driver. Thanks


Carb is a personal choice and depends on the intake. You don't want to use an adapter to mount a Q-jet to a squarebore manifold. The pattern is squarebore like Holley or AFB. I am not a fan of Holley, but they are a good quality carb I like the AFB squarebore over the Holley. As Army pointed out, the improved Edelbrock AVS2 seems to have a couple good features that I like - the annular booster ring in the primaries for better fuel atomization, and the adjustable secondary air flap like the Q-jet. I purchased a pair of 850 CFM AVS2 carbs for my dual quad build. Unknown if I will like them or not as the engine is still in pieces. But I do have a pair of older 750 AFB's as back-ups which do not have the features of the AVS2 should they not work as I hope.

So the 850CFM AVS2 would also be my pick. Easy to dial in if need be. There are a couple YouTube videos on the carb so you can see what they are all about if you have never had an AFB/AVS type carb. But, the choice is yours and if you like Holley carbs, go with what you know.


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## [email protected] (May 30, 2021)

Thanks for the info guys. I watched those videos on the Edelbrock AVS2 1913 and I’m feeling pretty good about going with it. One question is the CFM , Do you think the 650 or 800 CFM is best for my set up?


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## BLK69JUDGE (Jun 10, 2010)

a 360 offy what ??? 5964 ?? 5769 ??


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## [email protected] (May 30, 2021)

It’s a old school spread bore I’m not seeing a part number







b


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## armyadarkness (Dec 7, 2020)

[email protected] said:


> Thanks for the info guys. I watched those videos on the Edelbrock AVS2 1913 and I’m feeling pretty good about going with it. One question is the CFM , Do you think the 650 or 800 CFM is best for my set up?


My car pulled 30 hp less, on the dyno, with a 650. Pontiacs love big carbs. With the AVS2, there is no 750, so get the 800 and then tune it down if you like. Based on your build, it'll perform perfect, out of the box.

One thing to note, Edelbrocks wont tolerate (usually) more than 6psi of fuel pressure, so either have a regulator on hand, or get the Edelbrock fuel pump, which IMO is a much better option. It's not only preset on pressure, but it's a much better pump, built for modern fuel.


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## armyadarkness (Dec 7, 2020)

[email protected] said:


> It’s a old school spread bore I’m not seeing a part number
> View attachment 143441
> b


Unless Im missing something, your manifold is not a spreadbore


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## armyadarkness (Dec 7, 2020)

So... Quadrajets will not fit that offy.


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## [email protected] (May 30, 2021)

Thanks Darkness. Do you happen to know the part number for that fuel pump ? I’ll pick it up with the carb (800 CFM) this weekend. I’m going to have to do more research on this manifold. Some say spread bore, some say square bore.


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## armyadarkness (Dec 7, 2020)

Yeah, the manifold is far far far away from being a spread bore. The two are not remotely similar in appearance. Spreadbore has giant secondaries and small primaries, square bore has he primaries and secondaries, the same size.


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## armyadarkness (Dec 7, 2020)

Edelbrock Performer RPM Series fuel pump is for Pontiac V8


Edelbrock part #1713 Performer RPM Series fuel pump is for Pontiac V8 designed for use with all Edelbrock carburetors used in Performer or Performer RPM applications




www.edelbrock.com


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## armyadarkness (Dec 7, 2020)

FYI, edelbrock also makes a braided stainless fuel pump to carb line, complete with an fittings, a fuel inlet with a filter on it, and a heat insulator gasket. Not sure if youre trying to do it all cheap, but if not, they're all very "plug n play" and they'll definitely improve your car. The pump handles ethanol and the insulator is great for dealing with the heat crossover.


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## [email protected] (May 30, 2021)

Thank you brother. I appreciate the wealth of knowledge.


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## armyadarkness (Dec 7, 2020)

I'm a complete idiot, but even a broken clock is right twice a day.


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## BearGFR (Aug 25, 2008)

If you have a spreadbore manifold, nothing beats a properly set up QJet - nothing. All of them were capable of at least 750 CFM, some were more. It takes a pretty significant street engine to need more than a good QJet.

For square bore, yes it's true that Holley's are "infinitely tunable". The bad news is that you'll be spending the rest of infinity tuning it, in my experience at least. 

I'm running a reasonably warmed up solid roller 461 in my 69 GTO, and on the last build iteration I managed to convince myself that the engine "needed" more than my existing 800 cfm 455SD Qjet could provide so I converted to an AED 850 HO (Holley format) with annular boosters. It literally took me 12 full months - 1 year - of fiddling with it along with buying every jet, every pump nozzle, every pump cam, every power valve, every air bleed in the Holley parts book, even making my own bleeds and internal orifices using blanks, before I got it "right" in all modes of operation and that was with a nice digital air/fuel meter to help.

Personal experience - your mileage may vary, void where prohibited by law, past performance is not a guarantee of future return, slippery when wet.

Bear


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## Lemans guy (Oct 14, 2014)

And objects in the mirror may be closer than they appear…..


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## coyote595 (Dec 4, 2019)

There are Holley guys and non Holley guys. I ran a 750 Double Pumper #4779 for years on a built, solid cammed 406 with RA4 heads and it worked great. Never had a problem with it. Still have that carb up in my attic in a box. Just might use it again some day! As Jim said, carbs are a very personal choice. 

I had a 1963 Pontiac with a factory Carter AFB. That carb starved for fuel in hard right hand turns big time. That was really annoying. Other than that, it was a great carb.

The AVS sounds intriguing.

As others have said, that Offy manifold you have is definitely a square bore.


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## PontiacJim (Dec 29, 2012)

You want the 800 CFM for your engine/cam. 650 would run out of steam.

The intake is a squarebore. The 800CFM AVS2 uses all the same sized throttle plates whereas the 750 AFB, and assume the 650, has a slightly smaller sized primary throttle plate. The intake has dual pattern mounting holes for those carb studs, so just select the ones needed and use them.

Read the instructions when you get the carb. As Army pointed out, follow the guidelines on fuel pressure. I read the specs on the Edlebrock pump and it says 6 PSI, but some of these (maybe not this one) can put out even more pressure and then you will have flooding issues. So if this happens by chance, you will need a fuel pressure regulator. It does not seem to have an outlet for the 1/4" return line if you have one, the descriptions just says inlet and outlet size - but you can add this easy enough with a fitting if you have the return line.

I don't care for the fuel inlet's on these carbs as they are for rubber line hook-ups. I rather not have anything with rubber and ethanol laced gas/gas where it could let go and spill onto the engine and then......... Mr. Fire busts into the engine bay. 👹 So I went with Edelbrock #8090 fuel inlet which has the inverted female flare to accept a 3/8" fuel line. The fuel inlet will be on the passenger side so you will need to make a section of 3/8" steel line to joint the carb to the factory line - unless you make it all 1 piece. Don't know if you know how to bend fuel line?

You also want to use a fuel filter between the fuel pump and carb. Again, I prefer a hard line, 3/8", rather than short rubber lines and hose clamps. I am able to double flare/bend my own lines with the needed tools as this is something I learned a long time ago bending/making brake lines. You can get a quality fuel filter that will have the 3/8" female flares on each end so you can insert the line from the carb into it and then the line from the fuel pump into it. You may even want to wrap the filter/lines with a heat shield wrap. This is off Amazon just to show you, but Summit, Jegs, and others will also offer them.



Amazon.com : fuel line heat shield



When you get the carb, place the gasket on top of the manifold to make sure you will have enough room around the throttle blades so they do not hit. If any part of the intake hangs inside the gasket, you will have to do a little grinding to open up the manifold for fit otherwise the throttle blades will not fully open and you don't want to force them open and damage the carb. You may also need to trim any part of the carb gasket that does not have a surface for it to be clamped together by the carb base. The 4-hole gasket in the picture Army posted would not be a good choice as gasket material will hang into the manifold (as it is not a true 4-hole intake) and not be sealed/held into place - you don't want gasket material to break off later. So I would trim that gasket to fit the opening of the manifold which means it will appear more open and square rather than 4-holes.

And.......if you don't already know this, install and tighten up on the front water pump bolt and O-ring seal first to draw the intake forward and tight against the O-ring seal. Then tighten/torque your intake manifold bolts. This will spare you from having a possible water leak later.

I think that should cover it.  Ask more questions if need be and we will get you fixed up.


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## Droach6498 (Nov 1, 2020)

[email protected] said:


> Hi men, first time, long time. I am in need of help trying to figure out what kind of carb I will need for my motor set up. Here's what I'm working with. 1967 400 bored out .60,068 ram air cam, MSD ready to run distributor, Offenhauser 360 single quad manifold. This car is a Sunday street driver. Thanks


I just bought a carb from Steve Meno who advertises on Ebay he builds it from Holley and there other company cant remember FTS or something but you talk to him on the phone great guy takes about 4-5 days for him to build it. I paid for an 850cfm $559. So I shouldnt have to do much of anything with the specs I gave him. You have the same engine as me I had mine bored.068 but Im doing a stroker with parts from KRE. Carbs are all over Ebay, I think Edelbrock are a bit more simple


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## Pontiac#67 (Jun 15, 2021)

[email protected] said:


> Hi men, first time, long time. I am in need of help trying to figure out what kind of carb I will need for my motor set up. Here's what I'm working with. 1967 400 bored out .60,068 ram air cam, MSD ready to run distributor, Offenhauser 360 single quad manifold. This car is a Sunday street driver. Thanks


well your at 410 or so nothing a 750cfm can't handle.


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## [email protected] (May 30, 2021)

I went ahead and ordered the Edelbrock AVS2 800 CFM and the Edelbrock fuel pump. I’m looking to start on dropping the motor in this weekend.


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## armyadarkness (Dec 7, 2020)

Cool. The carbs are fun to tune.


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## BearGFR (Aug 25, 2008)

Let me add a "Amen" to PJ's assertion of never having fuel lines made out of rubber or any other 'fragile' material in the engine bay. I actually had an engine fire once in my 69 due to an undetected leaky fitting. It was a horrible horrible experience.

Bear


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