I have a 67 firebird 400 4spd. I have a Holley 650 on it now but the carb needs to be rebuilt. Should I keep and rebuild it or can you suggest a good replacement. Trying to go oem or something close. Thanks!
1967 Pontiac Firebird 400 4 Speed Convertible 1973 Opel GT
Nice car! Quadrajets are great and originally what came on these cars. They are also more cfm (750). Are you running stock intake? hows your throttle linkage set up?
Your care is nice too! Love the hood tach! It's a stock intake and throttle linkage. Is the stock quadrajet on the 67 400's 750cfm? I have been doing research on the quadrajets and the seem to run better than Holley's and Edelbrocks, but they are getting hard to find part for. What cfm do you recommend for a stock setup? Thanks!
1967 Pontiac Firebird 400 4 Speed Convertible 1973 Opel GT
I always thought that all pontiac V-8 cars had a 750cfm or larger carb. Chevy quadrajets had the 650cfm that was why they really don't work for pontiac applications. I might be wrong but that was my understanding. JOE
I`ve got a 650 Holley on my 400....drives very nice....got me to Estes Park and back in past August......14 mpg at 70 ....automatic.... 2.56 rear ..may not sound like much ,but I usually get "there" before others...LOL
2012 Mustang Boss 302 #1918, Competition Orange. FGF replacement 2006 Mustang V6 Pony, Vista Blue. Factory ordered. 2019 BMW X3 (Titled to the wife, but I'm always driving it for her. So I'm claiming it) Old projects, gone but not forgotten: 1967 FB 400, original CA car. After 22 years of work, trashed by the guy who was supposed to paint it. I had to sell it. 1980 Turbo Trans Am 1970 Mustang fastback, 351C 4Bbl, auto 1988 Mustang GT, 5 speed 1983 F-150 4x4, built 302 1994 Chevy K2500 HD 4x4, 454 TBI
I second salmon38, you cant go wrong with Cliff. He can rebuild qjets like noone else. He also sells rebuild kits if you want to try it yourself, get his book if you decide you want a project rebuilding it yourself.... great book.
When I had my Holley installed I had a bad carb from prev owner...my buddy (a professional restorer) told me I needed a new one., so I asked him which was the BEST carb to buy...and I got a very good answer "the carb you or someone you know likes to work on".....
it doesnt matter which is better if you cant get work done on it!
That's the difference between a Quadrajet and a Holley. If you go with the Holley, like B said, you better know somebody that knows how to work on it. If you go with a Qjet, once you put it on(unless you change your motor fundamentally), you don't ever have to touch it again.
Based on all the feedback, it sound like the quadrajet is what I want to go with. Is a reproduction of the original (7027272...400 cu.in. A.T.) a good option? I can't afford the an original...
1967 Pontiac Firebird 400 4 Speed Convertible 1973 Opel GT
That's the difference between a Quadrajet and a Holley. If you go with the Holley, like B said, you better know somebody that knows how to work on it. If you go with a Qjet, once you put it on(unless you change your motor fundamentally), you don't ever have to touch it again.
That's B.S. and not Bjorn's point at all. The point is, the best one to get, is the one you're comfortable setting up to begin with. Holley's do not require adjustments anymore than any other brand. I've set mine up 7 years ago, and haven't had to touch it. Even with a healthy cam, I can still start it up dead cold and within 10 seconds put it in gear and drive away.
A majority of the "complaint problems" are people that just don't understand tuning in general, can't figure out how to tune all the different circuits of that type of carb. That's why you'll find followers of each type.
Don't expect to pull a carb out of a box and it's tuned for your combination either. Setups are not a one size fits all. That's why people who buy from Cliff are pretty satisfied with his particular Qjets as he has enough experience to get it pretty close to in-tune before shipping it to you. Which is nice, but what are you going to do when you change a camshaft, change heads, gears, or move from Daytona Florida to deep in the Colorado mountains? Ship it back and forth to Cliff?
So forget all the "that brand sucks, this one's walks on water" b.s. and go with the one that you think you or a friend aren't going to be a afraid to adjust (whether it's a Carter, Qjet, or Holley). And then go out and buy a couple books and look research online about how to tune it. Whichever brand you choose, as long as you or a friend are willing and able to understand it and tuning in general, you'll be happy.
No reproductins, but some folks use the buick carbs since the pontiacs are getting hard to find. A good alternative if you're not after numbers matching. If you have the stock set up along with air cleaner you could use 67-70 carbs and will fit. 67-69 all had different throttle connectors but available through CI. Easy bolt on piece.
All carbs have pros and cons. Just some warnings, and some advice.
Quadrajets are a one-size-fits-all. You'll need to jet it, set the idle screws, idle, and depending on your car, you may need to adjust the secondaries to prevent bogging.
Taking a Q-jet apart takes some knowledge. You'll need to read a little on how to disassemble one, and how to reassemble it properly, or you'll have all sorts of tuning problems. Even a new rebuilt one may need to be taken apart to fix various issues. Just like any carb, you may need new gaskets when you disassemble it. Never hurts to have a rebuild kit just in case.
Holleys are a little easier. Parts are plentiful, gaskets can be found at any auto parts store.
My .02 cents ; since you already have the Holley 650, and it just needs to be rebuilt, this would be a great opportunity to take it apart and rebuild it, and get to know a little about what makes them tick. It will also be much cheaper than buying a rebuilt Q-jet.
Mike, Ease up dude. Just havin a little bit of fun. SHEESH. You're probably right in what you say but I've personally just never been a big fan of Holleys. I've only owned one and It was a POC. Ive owned several Qjets and loved all of them. Just sayin. Like they say, opinions are like a$$h*l#s...everybody's got one.(man, I thought that would get edited out)
That's the difference between a Quadrajet and a Holley. If you go with the Holley, like B said, you better know somebody that knows how to work on it. If you go with a Qjet, once you put it on(unless you change your motor fundamentally), you don't ever have to touch it again.
no, I didnt say that...I said , that NO MATTER WHICH you use, it should be best to use the one that YOU or Someone You Know is knowledgeable to work on....If you know Carter , buy it, if you dont work on it but your buddy does and he likes Q jet ,buy a Q jet...but as Mike said...since he has a Holley, why not fix it? Unless its too far gone to fix?? parts easy to come buy ,its an easy one to work on...
Mike, Ease up dude. Just havin a little bit of fun. SHEESH. You're probably right in what you say but I've personally just never been a big fan of Holleys. I've only owned one and It was a POC. Ive owned several Qjets and loved all of them. Just sayin. Like they say, opinions are like a$$h*l#s...everybody's got one.(man, I thought that would get edited out)
so, for you I wouldnt recommend a Holley...you should stick to QJets, esp. now if you are familiar with them....just my point excactly! As I dont work on mine , but my buddy does, I`ll stick with the Holley on the Bird...plus the Strombergs on the TR6 as he likes working on those too! LOL ...
This is something I've seen dozens of times over the years (and I'm old!). Someone has a problem with a carb, they want to junk it and buy another brand. Then years later, THAT carb needs a rebuild, and then they want to change brands again, each time referring to the last carb as a POS. As for a Holley vs. Q-Jet debate, all you have to look at are the people that switched from Brand A to Brand B, then ask why. 9 out of 10 times it's because their existing carb needed a rebuild, and they didn't want the hassle, so they bought the other brand. And of course a brand new carb will wake up your vehicle, so they claim their old carb was a POS.
IMO, rebuild the Holley 650. There's nothing more gratifying than rebuilding something yourself, and it works. It's an art that's been lost in this disposable, throwaway society we live in today.
Holleys are performance carbs, Quadrajets are not. Quadrajet rebuilders will tell you different, but Holleys have powered every NASCAR car for the past 50 years, every NHRA Pro Stock car since Pro Stock was invented. When engine builders are building for horsepower, they don't use a Quadrajet, unless the engine is for a restoration, or is required for class rules.
Love the passion guys, that's why I love this forum! I'm not knocking Holley and I have no problem with my holley. I have been doing slot of research and just wanted feedback on rebuilding it or going another route..and boy did I get it! Thanks!
1967 Pontiac Firebird 400 4 Speed Convertible 1973 Opel GT
Boy, I'm glad I stayed out of this one. Hope it all works out. (for everybody)
I used to be indecisive. Now I'm not sure. I feel like I am diagonally parked in a parallel universe. 1968 400 convertible (Scarlet) 1976 T/A - 455 LE (No Burt) 1976 T/A New baby, starting full restoration. 1968 350 - 4 speed 'vert - 400 clone (the Beast!) 1968 350 convertible - Wife's car now- 400 clone (Aleutian Blue) (Blue Angel) 2008 Durango - DD 2008 GXP - New one from NH is AWESOME! 2017 Durango Citadel - Modern is nice! HEMI is amazing! 1998 Silverado Z71 - Father-daughter project 1968 400 coupe - R/A clone (Blue Pearl) (sold) 1967 326 convertible - Sold 1980 T/A SE Bandit - Sold
Mike, Ease up dude. Just havin a little bit of fun. SHEESH.
Bob, I don't wanna talk to you no more, you empty headed animal food trough wiper! I fart in your general direction! You mother was a hamster and your father smelt of elderberries.
Now go away or I shall taunt you a second time! LOL!
This is something I've seen dozens of times over the years (and I'm old!). Someone has a problem with a carb, they want to junk it and buy another brand.
Or, turns out it's not even the carb. A vacuum leak, faulty ignition, or just incorrect timing, or dwell settings. Then either the carb swap inadvertently fixes it (which is possible in the case of the vacuum leak), they do several changes at the same time that end up fixing the problem, or the problem gets fixed after they realize it's still running wrong with the new brand carb. In most of these cases what they remember later on is <insert brand here> made it run like cow pies
I don't see any need for carb wars, as any brand will run correctly for a long time if setup right (assuming your not running a knockoff of the original brand, in which case, all bets are off).
One thing we haven't talked about is thast most Holleys are square bores right? So maybe we're talking extra expense if cahnging from one brand,or type, to the other. Might very well give an advantage as far money spent on a new intake as well.
I used to be indecisive. Now I'm not sure. I feel like I am diagonally parked in a parallel universe. 1968 400 convertible (Scarlet) 1976 T/A - 455 LE (No Burt) 1976 T/A New baby, starting full restoration. 1968 350 - 4 speed 'vert - 400 clone (the Beast!) 1968 350 convertible - Wife's car now- 400 clone (Aleutian Blue) (Blue Angel) 2008 Durango - DD 2008 GXP - New one from NH is AWESOME! 2017 Durango Citadel - Modern is nice! HEMI is amazing! 1998 Silverado Z71 - Father-daughter project 1968 400 coupe - R/A clone (Blue Pearl) (sold) 1967 326 convertible - Sold 1980 T/A SE Bandit - Sold
This is something I've seen dozens of times over the years (and I'm old!). Someone has a problem with a carb, they want to junk it and buy another brand.
I don't see any need for carb wars, as any brand will run correctly for a long time if setup right (assuming your not running a knockoff of the original brand, in which case, all bets are off).
exactly, my friends point....get they one your or your friend is most familiar with = easy to work on! lol
my friend used to race, maybe thats why he likes and is familiar with Holleys....
and I `m getting the same gas mileage as my friends running QJets!
one thing to remember though is that a bigger carb doesnt necessarily get you better power...a carb can be too big....spitting out the gas thru exhaust or mix in the oil...my 400 likes a Holley 650...
my 302 I had in my "Sebring" (Austin Healey fiber glass replica) came with a Holley 650 from prev owner....engine had gas in the oil, carb was waaay to big for that car/engine combo...it got 12-13 mpg....I bought a smaller Holley for it(I forget the size), and car was quicker, got 19 mpg and no gas in the oil! then we put that used 650 on my sons 350 Chevy in his TP21! perfect for it.
Been mess'n with holleys and q-jets since the 70's. Holley's are easier. But when done right, q-jets out power and give better milage at least up 700 hp. Havent tried q-jets past that cause use 4500 dominators.
I think we touched on the square bore thing earlier. He already has a Holley 650 spreadbore, so no adapter would be necessary.
Originally Posted By Region Warrior
Been mess'n with holleys and q-jets since the 70's. Holley's are easier. But when done right, q-jets out power and give better milage at least up 700 hp. Havent tried q-jets past that cause use 4500 dominators.
Well, I'd have to disagree on that. A Q-Jet will not out power a Holley. A Q-jet may provide equal performance under wide open throttle. Q-Jets are not designed as a wide open throttle carb, they were designed as a street carb. And they do that very well.
Quadrajets will run well on a high 12's or a 13-second car. Once you dip into the 12's, there are some shortcomings you have to address. Quadrajets have a tiny float bowl. You need a very good fuel system that will keep the volume up to overcome that small float bowl. Without a decent pump and some good sized fuel line, a Quadrajet will begin to starve on the top end. Beyond the 12's, you need a hefty fuel line (min 3/8"), and an electric pump, preferably bypassing the mechanical.
The GM engineers knew about Holley's superior performance, that's why they chose to use a Holley on their fastest cars. It really went against the grain to do that, considering companies like GM used Rochester Products exclusively after 1966. But the engineers knew they needed a Holley when they passed a certain point. Holleys were racing carburetors.
For those choosing between the two types of carbs, again, go with the carb that you know a little more about, stick with the one you already have, and rebuild it yourself. Both types of carbs will work well.
BTW, I don't own a carb rebuilding business, so I do not have a vested interest in convincing people to run one carb or another. You have to be careful about that, because on the web, people can give their opinion, then they get your business.
Ok, you pulled my knob Agree for the most part. Use what you know and like. 850 holley doesnt make mine any faster. If change rear grs, and tune for it, 11.5's. Up compression 2 pts and tune some more, 11.0's. Dont want to pay the price for fuel since cruise more then race. Drives the chevy dodge ford guys nuts when they see me pump'n 87 octane Reguardless, over 500 hp, need larger line and better pump reguardless of carb. Hmmm...Pontiac thought they where fine for RAIV's and SD455's. BTY, quite a few guys run 10's with q-jets. Stacy McCarty runs 9.80's with a rebuilt junk yard q-jet. Granted, his car is exotic.
One last point on q-jets vs holleys for street performance, or just strip. Once set up correct, dont even need primary needles. Need more/less fuel for weather conditions?, just swap secondary needles(1 screw on the hanger). No gasket worries, no gas drain'n or spill. Holley have to remove the bowls to change jets. What a mess. And have spare gaskets on hand jic.
Yep, there are a few guys running 10's with a Q-jet. Killer fuel systems, 1/2 line, and modified internals. I've modified some of those carbs, knife-edged the blades, ground out the fuel bowl for more volume, modified the secondaries to use jets, cut out the primary ring boosters, etc. They aren't stock Q-jets.
And for every car that's running 10's with a Q-jet, there are about 1,000 guys running 10's with a Holley.
I ran 11.60's in street trim, full exhaust, street tires, 2400 converter, 3.42 gear, with an Edelbrock 850 Q-jet. And I too used pump gas, although the 93 octane variety. I played around with a Holley HP950, and out-of-the-box I encountered severe traction problems under 40 mph, something I never had with the Q-jet. I went back to the Q-jet because I drove my car more on the street. I currently have a Holley 3-barrel. For a 40-year old carb, it runs like a champ.
Factory cars, oh oh, this is near and dear to me.
The factory Pontiac RAIV used a Quadrajet. When the engineers designed the ultimate 400 engine, known as the RAV, higher revving, with huge ports, they chose the Holley 780. That went completely against policy. GM used Rochester carbs exclusively, so this was not a minor change. Pontiac engineers designed a different air cleaner base, they would require all new Service Manual Supplements to be printed and sent to all Pontiac dealers on how to tune and maintain Holley carbs, all the mechanics would need to be trained on a new type of carb. Plus, GM was tight on their warranty issues, so allowing a part from an outside company to sit on top of one of their Pontiac engines was not to be taken lightly. Obviously, Pontiac engineers felt pretty strongly about using a Holley. It made more power, and they knew the RAV would be on race tracks.
Others
The 1970 Chevrolet LS5 454 used a Quadrajet. The top of the line, highest horsepower Chevrolet was the 450hp LS6, which used a Holley. 1969 Chevy 396 and 427's used a Quadrajet, but the 427 high-perf models, including the L-88 and ZL-1, used a Holley. They also used Holleys on the tri-carb L-88 model, odd considering Rochester had 2-barrel carbs stacked up from the old Pontiac and Oldsmobile programs.
1969 Ford 428CJ used an Autolite carb. The monster Boss 429 Mustang used a Holley. All Ford race cars used Holley carbs, including their 1969-1970 Boss 302.
The 1970 Buick Stage 1 used a Quadrajet. Buick's racing engine was the Stage II, available over the parts counter, which used a Holley.
Mopar wanted to use Holleys on their 1966-1971 street 426 Hemi, but the intake carb spacing wouldn't allow the Holley float bowls to clear. Their street engines used Carter carbs, the racing engines used Holleys.
Pontiac SD-455 was designed with a Holley, but due to emissions requirements, they were straddled with a Quadrajet. When the engineers prepped an SD-455 for competition, and to see how much power it would make on the engine stand, they used a Holley.
OK I have to through my limited experience in here.
By far the worst experience I have had with a carb was the edelbrock. I bought the tuning kit and never could make that thing run without major bog. The older models had no way of tunning the secondary flap. I ran a Holley 3310 before that. It was cheap and rightfully so but worked all right.
My brother had his 468 stocker motor on the dyno a couple years back so we got to do some testing with it. He bought a Holley avenger. I think it was a 825. The jets needed to come up 20 points. This increased the HP by about 60.
I have a 1969 Q-jet modified by cliff that we tested also. It was within 10hp with no tuning. It was ran on the motor once just to see how it would do. Now it's on my 455.
I have read many of Cliff's post on the subject and he can typically get the numbers closer to like 2-3 hp but the Holley typically win the hp war. That being said the Q-jet with the smaller primaries can typically get better fuel mileage.
My recent expirence with the same 1969 Q-Jet and a lumpy H10 Ultradyn cam has not be good. The feul system as mention above can not keep up with the small fuel bowls so I'm changing over to 1/2 fuel line and sending unit. The low vacuum of the cam is also and issue as I have nozzel drizzel from the higher RPM and having the primaries open to far. This makes for some smelly raw gas idleing and bad looking spark plugs. I could mess with the air bypass or drill holes in the primaries but I don't want to screw up a good carb and I'm working on a roller cam install for the spring.
Some will no doubt argue with me on this but my opinion is a car that is more strip then street go with the holley. The larger feul bowls and four idle circuits makes it a good choice. If your car is more street them strip then the Q-jet with the smaller primaries gives good milage, that and the high velocity off idle performance. Where the issues seem to appear is with the larger cubic inches, larger cams over the 230 duration with tighter LSA.
Holley makes many nice carbs and the Qjets have been proven to do well over the years and no matter what you pick it will need tuning to run to its potential.
The nozzle drip is pretty common on Q-Jets, especially as you step up the cam specs. To compensate for the radical cam and low vacuum, you need to raise the idle with the throttle screw, but the air bleeds are too small, so you get nozzle drip at idle. Also, with a radical cam with little vacuum, you'll lift the primary rods up, and the engine will want to stall. Very touchy situation.
A little known fact : Oldsmobile designed a special Quadrajet for their 1970 W-30 that did not use primary rods. It ran off the jets. I believe Cliff has made this modification to some customers Q-jets.
I really do like Q-jets, and as I mentioned earlier, I've used them for decades, and like to work on them. When they're dialed in, they're wonderful carbs. Unfortunately, one of the greatest advantages to a Quadrajet WAS cost. They were sometimes FREE, or maybe $5 at a swap meet. They made millions of them. No one wanted them. But now they're pretty expensive, especially from a tuner. A rebuilt one can run $400-$500.
The Q-jet only needs 4-5 psi fuel pressure to run properly. I've seen them run fine at 3 psi. It's all about volume, not pressure. Holleys run best at 7-8 psi.
Of course, the nicest thing about a Q-jet is that it's factory, it's stock appearing! They run great on a stock or mildly modified car. When you get into the 400+ hp range, they need a 'little' work, and over 500+ hp, you really need to read up on the inner workings, or you can use a rebuilder like Cliff, who does fantastic work.
Yep, there are a few guys running 10's with a Q-jet. Killer fuel systems, 1/2 line, and modified internals. I've modified some of those carbs, knife-edged the blades, ground out the fuel bowl for more volume, modified the secondaries to use jets, cut out the primary ring boosters, etc. They aren't stock Q-jets.
None of thats nessesary.
And for every car that's running 10's with a Q-jet, there are about 1,000 guys running 10's with a Holley.
Cause they dont know no better.
I ran 11.60's in street trim, full exhaust, street tires, 2400 converter, 3.42 gear, with an Edelbrock 850 Q-jet. And I too used pump gas, although the 93 octane variety. I played around with a Holley HP950, and out-of-the-box I encountered severe traction problems under 40 mph, something I never had with the Q-jet. I went back to the Q-jet because I drove my car more on the street. I currently have a Holley 3-barrel. For a 40-year old carb, it runs like a champ.
Edelbrock models suck.
Factory cars, oh oh, this is near and dear to me.
The factory Pontiac RAIV used a Quadrajet. When the engineers designed the ultimate 400 engine, known as the RAV, higher revving, with huge ports, they chose the Holley 780. That went completely against policy. GM used Rochester carbs exclusively, so this was not a minor change. Pontiac engineers designed a different air cleaner base, they would require all new Service Manual Supplements to be printed and sent to all Pontiac dealers on how to tune and maintain Holley carbs, all the mechanics would need to be trained on a new type of carb. Plus, GM was tight on their warranty issues, so allowing a part from an outside company to sit on top of one of their Pontiac engines was not to be taken lightly. Obviously, Pontiac engineers felt pretty strongly about using a Holley. It made more power, and they knew the RAV would be on race tracks.
The 780's on RAV's where replaced with bigger cfm carbs by everyone. Besides, the heads flowed more then a 400 ci could swallow.
Others
The 1970 Chevrolet LS5 454 used a Quadrajet. The top of the line, highest horsepower Chevrolet was the 450hp LS6, which used a Holley. 1969 Chevy 396 and 427's used a Quadrajet, but the 427 high-perf models, including the L-88 and ZL-1, used a Holley. They also used Holleys on the tri-carb L-88 model, odd considering Rochester had 2-barrel carbs stacked up from the old Pontiac and Oldsmobile programs.
Not sure why, maybe chevy didnt want to take the time to make a q-jet work.
1969 Ford 428CJ used an Autolite carb. The monster Boss 429 Mustang used a Holley. All Ford race cars used Holley carbs, including their 1969-1970 Boss 302.
Ford.
The 1970 Buick Stage 1 used a Quadrajet. Buick's racing engine was the Stage II, available over the parts counter, which used a Holley.
Same reason as chevy.
Mopar wanted to use Holleys on their 1966-1971 street 426 Hemi, but the intake carb spacing wouldn't allow the Holley float bowls to clear. Their street engines used Carter carbs, the racing engines used Holleys.
Thermoquads a good once the defects are fixed.
Pontiac SD-455 was designed with a Holley, but due to emissions requirements, they were straddled with a Quadrajet. When the engineers prepped an SD-455 for competition, and to see how much power it would make on the engine stand, they used a Holley.
Pontiac made the q-jet work.
This is all great debate.
Agree. Not sure how to break down my responces. Have to scroll thru.
How much are the original Rochester carbs for a 67 firebird 400 4spd worth? What would you pay for one that has the gold tag and has been rebuilt? Thanks!
1967 Pontiac Firebird 400 4 Speed Convertible 1973 Opel GT
Depends on how bad someone wants it. Intake/carb/air cleaner/exhuast mans/exhuast/wheels where missing when i bought mine in 79. Everything else original. Now older wanting to repair rust-n-repaint car, be nice to make original again. But "to me" not worth spending what most others will for same parts. If nice at a price can afford, then i'd buy'm.
![[Linked Image from i116.photobucket.com]](http://i116.photobucket.com/albums/o38/Lafann/13Firebird32_zpsc3472fae-1_zps1a9b372c-1_zps6cc6e08b.jpg)
It's an art that's been lost in this disposable, throwaway society we live in today. 
