Buick 350 carbs

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daves73

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1973 Buick Century Luxus
Hi, looking for some info on what would be a good fit carburetor wise for a 1973 Buick 350 that has been upgraded with the TA 212 cam and stage 1 TA manifold. Running headers, upgraded torque converter based on the cam, posi rear end with 3.42 gears. I've had such conflicting info saying the Buick 350 needs to be at least a 750, to don't even think about putting anything more than something like a Edelbrock 600. Its just a street cruiser with the odd highway travel to some car shows so no racing. Saw on a thread somewhere that a tech at T/A performance suggested no more that the 600? So boys and girls any info you could provide would be greatly appreciated. Thanks.
 

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2007 Lucerne CXL. and 1995 Lesabre currently, past 1973 Riviera, 1968 Riviera
A stock 4 bl Quadrajet could be used and upgraded, depending on the stamping it's a 750 or 800 CFM. There's nothing wrong with them, just they are a little harder to work on then a Holley so that's why they got yanked off most the time. More is better law doesn't apply to carburetors, if you have the stock 4 bl Quadrajet it can be used and tweaked.

Just another option.
 
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daves73

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Thanks for the reply, it is the 750 Quadrajet sitting on it now (actually the motor isn't back in the car after the rebuild) so thought it would be the time to make a decision on keeping it or going with something like the 600.. sitting here thinking in the grand scheme of things after spending the money on a rebuild the $ spent on a second carb like the Edelbrock is so insignificant that why not get one and have it calibrated and do my own testing on the performance and see if it really saves that much on gas or overall performance. Maybe that way I could post my findings and help someone down the line with the same question..... ( :
 
955
275
63
Illinois
Buick Ownership
2007 Lucerne CXL. and 1995 Lesabre currently, past 1973 Riviera, 1968 Riviera
Understand on your direction, I don't have any experience on the Edelbrock just Holley, Quadrajet with a bunch of single barrel and 2 barrel, but the Holley's were pretty simple with lots of tuning parts and have to imagine Edelbrock is the same.

There's a mathematical formula to figure out based on engine size and components to get a good guesstimate on carb size, I'm sure there's something online. Needed it once back in the dark ages and that been long forgotten LOL.
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daves73

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my stepdaughter is graduating from university in mathematical stats so I'll let her deal with those kind of formulas!! ( :
 

HotZ28

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I had plenty of those cars from those years (GTO's (400 cui) 442's (400 cui & 455cui) 350 cui Corvettes & GS 455-Buick's which were all equipped with the quadrajet and they all performed flawlessly with only some slight modifications for performance. You need nothing else if the carb is not leaking fuel through the fuel bowl, which can present another problem during starting.
 
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daves73

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Thanks for the info HotZ28 seems like most people are saying the same thing about the Quadrajet..... Certainly cheaper just holding on to what I have. I'll re-post once I get it back on the road and see how she preforms.
 

L J

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Quadrajet is way to go if spreadbore manifold. I believe Jet still have versions that will flow more then you will need..like version on Pontiac 455 SD.
LJ
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LARRY70GS

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As soon as someone mentions that formula, you can pretty much know that they will recommend a smaller carburetor. Here is the truth, Buicks like bigger carburetors at the track, put one on, they go faster. On the street, a smaller carburetor may have better throttle response and get better mileage. Regardless, the best carburetor has to be calibrated for your combination, so no off the shelf carburetor will be perfect until it is calibrated or tweeked for your engine.

Having said that, IMO, there is no better carburetor for a street car than the Quadrajet. Edelbrock carburetors cannot compare, and they are square bore carburetors. The Edelbrock carburetor will never be as responsive and seamless as a good Q-jet. The stock Q-jet was a 750 CFM carburetor, but that is misleading because a Q-jet uses an air valve up top above the secondary throttle blades. The air valve only opens enough depending on actual demand, so the Q-jet effectively sizes air flow to engine demand. For the 212 cam, a q-jet will need some calibration of the idle system. What you need is a custom calibrated Q-jet. The Quadrajet was a very sophisticated carburetor and it was calibrated by GM for the engine line it was intended for. You therefore cannot just bolt on any Q-jet you find on any engine and expect it to run right. It is way more than jets and rods BTW. I recommend Ken Gies at Everyday Performance. He is a Buick guy, and he has lots of experience with the 212 cam, he know what it needs from a carburetor. Give him a call, he'll fix you up.

Everyday Performance Rebuilt Rochester Quadrajet Carburetor Positraction Axle Store

BTW, click on the youtube links in my signature. That first one is an 11.85 @ 114 MPH in 90* heat, using a Q-jet.

You'll also want to check out www.v8buick.com
 
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L J

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In 1970 when I wanted to upgrade Quadrajet on my 70 TA went with Carter Thermoquad. It was spreadbore carb with resin body that would keep fuel cooler. The good thing about it if my memory serves me...is it was available in 850 cfm or 1000 cfm versions.
It was a good design and when at dragstrip not many cars could keep up with me. I had to make some good shifts with my manual to beat my buddies 69 Mach 1 with 428 Cobrajet and C6 auto.
LJ
 
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2007 Lucerne CXL. and 1995 Lesabre currently, past 1973 Riviera, 1968 Riviera
Just a reference on the math to coming up with a proper aftermarket carb size. The online quick calculations omitted some of the other configuration needed to make it a complete formula. Once I had set mine up I didn't need to keep it in my head, but this does a good job of describing it.

How Big A Carb Do You Need?
 

LARRY70GS

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In 1970 when I wanted to upgrade Quadrajet on my 70 TA went with Carter Thermoquad. It was spreadbore carb with resin body that would keep fuel cooler. The good thing about it if my memory serves me...is it was available in 850 cfm or 1000 cfm versions.
It was a good design and when at dragstrip not many cars could keep up with me. I had to make some good shifts with my manual to beat my buddies 69 Mach 1 with 428 Cobrajet and C6 auto.
LJ
Yes, the Thermoquad is an excellent carburetor. I know several Buick racers that still use them. Not as easy to find as a Q-jet. Carter made Thermoquads until about 1980. Many of them were the 750 CFM versions, not the 850 and 1000 that are the best.
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Yes, I know we are talking about old cars (and race cars) and I'm being facetious;

I thought Carburetors, Ignition Points and Condensers (capacitors), Coils, Timong Lights, Dwell Meters, Sun Machines etc etc etc. were all things from the past. Most younger people have no idea what they are, other than Carburetors.
 

LARRY70GS

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Yes, I know we are talking about old cars (and race cars) and I'm being facetious;

I thought Carburetors, Ignition Points and Condensers (capacitors), Coils, Timong Lights, Dwell Meters, Sun Machines etc etc etc. were all things from the past. Most younger people have no idea what they are, other than Carburetors.
They are indeed from the past. There are some who still use points, but most have converted over to electronic ignition of some sort. Older cars still require timing lights to check and adjust timing. New cars still have coils, except there is one for each cylinder. Most young people are into the cars of their generation, and they still hot rod them, it just involves forced induction, fuel injection, and nitrous. I have a 1970 Big Block GS, a car I admired when I was 14-18 years old. Finally acquired one when I had more money in my 40's.
 

HotZ28

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I also bought a new GS-455 cui in 1970 for $4500. The street racing was rapid back then and the Hemi Plymouth was dominating! All of my friends said I was crazy for buying an "old man's car" (Buick) GS. We finally meet with the Hemi that dominated street racing and the "old man Buick" won by two car lengths in the 1/4 mile. It had more torque/HP than the Hemi ever had.
 

LARRY70GS

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If you could hook a 1970 GS455 Stage1 on the street, they were lethal. Gobs of low and mid range torque. That and the Stage 1 came with a BB coded 400 transmission. It was specially calibrated to downshift from 3rd gear to first at speeds under 35 MPH. From a roll, the trans would go down into first, scream to 5200, and shift second and the car was gone! My GS will do that, but I can't hook it, the car goes sideways on regular street radials. That's to be expected with torque like this,

Motor2FinalPull.jpg
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