[4dblnkldude]

I am working on an 81 Trans Am with a 77 400 engine. The carb should be rebuilt. I removed it and it is dirty everywhere and the car did not rev above 2500 rpm. It did not look like the choke was opening...? It has a 77 oldsmobile quadrajet on it. Is this carb OK? Is there any reason not to use it? Will it perform just as well as a Pontiac quadrajet? I am so tempted to put a 3310 on it and a performer intake but I would like to put a shaker hood on this car eventually. The engine will probably not even be rebuilt if it runs good. Probably exhaust would be the only modification. And this car is just going to be a street cruiser..maybe a couple smoke shows here and there and a strip run for fun.

[chiphead]

As with anything carburetor, what is the number on the Quadrajet? Only thing I know about the late 70s olds units is some of them had the early style apt which is really hard to tune. I don't think Pontiac vs. Chevy vs whatever type of Quadrajet from the late 70s early 80s really matters, except for some of the large main air bleed carbs or the electronic units. There were some throttle linkage differences too but you can overcome it. They were all 750 or 800 CFM apt carbs. Once you recalibrate them, they work pretty well. I would definitely converted to electric choke if it doesn't already have it. Cliff and a couple other guys can get any part you need for it

[steve25]

If the motor is all original other then Carb wise then it very likely needs a timing chain and gears along with the Carb rebuilt and clabrated before you do smoke shows !

Pull all the plugs out , remove the Distributor cap and then grab the Balancer and spin it back & forth a small distance.

The lack in how the Distributor rotor follows the movement of the Crank will tell you how the chain and gears are.

A retarted Cam setting due to a loose chain will cost you 25 hp before you can bat a eye not to mention make the motor run hot!

[4dblnkldude]

Thanks guys! I'll check the timing gears. The carb was on the car when I got it.

[Navy Horn 16]

Once you get the rest of the engine sorted, I strongly recommend these guys for your Q-jet rebuild.

https://quadrajetpower.com/

They are just down the road from here in the Texas hill country, and they did a high level build for me. If you want a Pontiac Q-Jet, they have them on the shelf.

[ponyakr]

"...It has a 77 oldsmobile quadrajet on it. Is this carb OK?..."

Yes.

"...Is there any reason not to use it?..."

No.

"...Will it perform just as well as a Pontiac quadrajet?..."

Yes.

"...I strongly recommend these guys for your Q-jet rebuild..."

If you are closer to the West coast, than to Texas, you might wanna use SMI. If you're closer to the East coast, you might wanna use Everyday Performance.

https://www.smicarburetor.com/produc...D2/9/sfID3/100

http://www.everyday-performance.com/...arburetors.htm

If you wanna rebuild it yourself, lots of guys here buy rebuild parts from Cliff.

https://cliffshighperformance.com/

[4dblnkldude]

My local carb guy here said to throw it over the hill today and put on a holley. I guess I'll rebuild it and throw it back on for now.

[GTOLou]

Originally Posted by 4dblnkldude

My local carb guy here said to throw it over the hill today and put on a holley. I guess I'll rebuild it and throw it back on for now.

I've had Cliff do several qjet carbs over the years - I would absolutely check w/ him about a rebuild before I went elsewhere. You just might catch him without a terrible backlog.

Jeff Esmel/Shaker455 can do any carb as well. He's kind of the gold standard for a holly - but he can do a qjet as well.

I'd try those first - at least if it was me.

[77 TRASHCAN]

Originally Posted by GTOLou

I've had Cliff do several qjet carbs over the years - I would absolutely check w/ him about a rebuild before I went elsewhere. You just might catch him without a terrible backlog.

Jeff Esmel/Shaker455 can do any carb as well. He's kind of the gold standard for a holly - but he can do a qjet as well.

I'd try those first - at least if it was me.

My thoughts, same!!!

[4dblnkldude]

I got lucky, long story but was at a birthday party for my brother in laws little sister and spotted some parts in the corner. I recognized it as a pontiac right away. He sold it to me for 50 bucks, scratched off the numbers and it was the exact one for my engine..7274. I had it rebuilt by another local guy and the color was perfect. I put it on and it runs great!!!

[mgarblik]

Originally Posted by 4dblnkldude

My local carb guy here said to throw it over the hill today and put on a holley. I guess I'll rebuild it and throw it back on for now.

Unless he was just kidding around with you, I wouldn't let him touch a lawnmower carburetor with that attitude. A properly set-up and calibrated Q-jet will have better driveability, better idle quality, and outperform a generic Holley replacement every single time. Generic replacement Holley carburetors are for those who don't understand fuel systems and carburetors. They are super simple and the car will run with one bolted on, but you can do better with Cliff's book, his Q-jet parts and a Saturday with nothing else to do. Good luck.

[4dblnkldude]

Originally Posted by mgarblik

Unless he was just kidding around with you, I wouldn't let him touch a lawnmower carburetor with that attitude. A properly set-up and calibrated Q-jet will have better driveability, better idle quality, and outperform a generic Holley replacement every single time. Generic replacement Holley carburetors are for those who don't understand fuel systems and carburetors. They are super simple and the car will run with one bolted on, but you can do better with Cliff's book, his Q-jet parts and a Saturday with nothing else to do. Good luck.

No he was not kidding. Thats why I didn't take it to him. He's very good with the holleys and is known all in the northeast. He is cocky, but I like him.

[Cliff R]

The post 1976 and later Olds Q-jets are excellent. They are equally as good as an other front inlet Pontiac or Buick carb from that period. They need a little help in a few areas being emission calibrated, but nothing out there will outrun them on the dyno or at the track once you get them up to par for what you are doing.

I chuckle to myself when I see folks still stuck in the 60's with this "put a Holley on it and thru the Quadra-junk in the dumpster" deal. I've set up thousands of Q-jets at this point to replace modern aftermarket "high performance" carburetors because folks are having such poor success with them.

Case in point (I love real stories). One of my best friends owns a tree removal service. The hired help dogs his 1 ton Chevy dump truck hard enough to spin a bearing in the original 350 engine. So he works out a deal with a local Chevy "guru" to replace the 350 engine in trade for removing a bunch of trees on his property.

The install doesn't go all that well, and the "guru" actually called me when my friend told him I was a carb builder. He said that the new engine needed at least a 750cfm carb, preferably a "double pumper". I told him I didn't mess with those, only did Q-jets, he quickly responded that he wouldn't have a Quadraj-Junk on any of his engines, so I quickly ended the conversation and knew my friend was in trouble.

I mentioned to my friend that the "406" the guy was installing required an externally balanced flywheel, no one listened and it shook out of it's mounts adding couple of weeks to the engine swap to figure out that deal. Anyhow, from day one my friend absolutely HATES the new engine. It's a complete "turd" for power production in the RPM he runs it, 406, some sort of Comp XE cam, single plane intake, Holley Street Avenger carb, Summit HEI. It sucks down 20 dollars worth of fuel for 20 mile short trips (pulls a chipper behind it, loaded with gear and/or dump bed full of wood chips. He's getting 2-3 MPG's best case scenario.

So it goes back to the "builder" countless times for various issues, oil leaks, not running well, heavy fuel consumption, etc. Then he starts showing up with it here. I get tired of seeing it coming up the driveway and rescuing him off job sites when it refuses to start or stay running. I must have had the bowls off that thing 15 times, cleaning out the metering blocks, new N/S assemblies, attempts at jetting to improve things, it just refuses to respond or work well no matter what we do to it. I think it's pretty much possessed at this point and finally tell my friend that the next time he calls me I'm replacing the carb.

So the call comes in, we send a flat bed for it, replace the carb with a stone stock Motorhome Q-jet with an E-choke on it not claimed by a customer. It starts instantly and runs flawlessly except for not wanting to "settle down" at idle speed requiring stronger springs and slight mechanical curve modifications to the Summit "high performance" HEI distributor (sound familiar?).

Power is also restored, and fuel economy, and dead solid reliable. Haven't heard from him since about the truck (been about 2 years now), and I'm on his "Christmas List" from here on out.

This sort of result is typical from what I'm seeing with a lot of this later aftermarket stuff, carbs, distributors, etc. Mass produced, offshore components and piss-poor quality. This Street Avenger Holley was defective from day one. I know my way around that design pretty good, and it was delaminating on this new fuel and the electric choke wasn't worth two squirts of duck-poop from day one. Being in this business full time I get to hear all the stories and similar experiences with these parts. Of course with enough effort one can pretty much make anything work, but for long term service or in an application as described above one of those carbs would be LAST on my list.....FWIW......Cliff

[JSchmitz]

Originally Posted by Cliff R

The post 1976 and later Olds Q-jets are excellent. They are equally as good as an other front inlet Pontiac or Buick carb from that period. They need a little help in a few areas being emission calibrated, but nothing out there will outrun them on the dyno or at the track once you get them up to par for what you are doing.

I chuckle to myself when I see folks still stuck in the 60's with this "put a Holley on it and thru the Quadra-junk in the dumpster" deal. I've set up thousands of Q-jets at this point to replace modern aftermarket "high performance" carburetors because folks are having such poor success with them.

Case in point (I love real stories). One of my best friends owns a tree removal service. The hired help dogs his 1 ton Chevy dump truck hard enough to spin a bearing in the original 350 engine. So he works out a deal with a local Chevy "guru" to replace the 350 engine in trade for removing a bunch of trees on his property.

The install doesn't go all that well, and the "guru" actually called me when my friend told him I was a carb builder. He said that the new engine needed at least a 750cfm carb, preferably a "double pumper". I told him I didn't mess with those, only did Q-jets, he quickly responded that he wouldn't have a Quadraj-Junk on any of his engines, so I quickly ended the conversation and knew my friend was in trouble.

I mentioned to my friend that the "406" the guy was installing required an externally balanced flywheel, no one listened and it shook out of it's mounts adding couple of weeks to the engine swap to figure out that deal. Anyhow, from day one my friend absolutely HATES the new engine. It's a complete "turd" for power production in the RPM he runs it, 406, some sort of Comp XE cam, single plane intake, Holley Street Avenger carb, Summit HEI. It sucks down 20 dollars worth of fuel for 20 mile short trips (pulls a chipper behind it, loaded with gear and/or dump bed full of wood chips. He's getting 2-3 MPG's best case scenario.

So it goes back to the "builder" countless times for various issues, oil leaks, not running well, heavy fuel consumption, etc. Then he starts showing up with it here. I get tired of seeing it coming up the driveway and rescuing him off job sites when it refuses to start or stay running. I must have had the bowls off that thing 15 times, cleaning out the metering blocks, new N/S assemblies, attempts at jetting to improve things, it just refuses to respond or work well no matter what we do to it. I think it's pretty much possessed at this point and finally tell my friend that the next time he calls me I'm replacing the carb.

So the call comes in, we send a flat bed for it, replace the carb with a stone stock Motorhome Q-jet with an E-choke on it not claimed by a customer. It starts instantly and runs flawlessly except for not wanting to "settle down" at idle speed requiring stronger springs and slight mechanical curve modifications to the Summit "high performance" HEI distributor (sound familiar?).

Power is also restored, and fuel economy, and dead solid reliable. Haven't heard from him since about the truck (been about 2 years now), and I'm on his "Christmas List" from here on out.

This sort of result is typical from what I'm seeing with a lot of this later aftermarket stuff, carbs, distributors, etc. Mass produced, offshore components and piss-poor quality. This Street Avenger Holley was defective from day one. I know my way around that design pretty good, and it was delaminating on this new fuel and the electric choke wasn't worth two squirts of duck-poop from day one. Being in this business full time I get to hear all the stories and similar experiences with these parts. Of course with enough effort one can pretty much make anything work, but for long term service or in an application as described above one of those carbs would be LAST on my list.....FWIW......Cliff

Cleaned out 15 times? What was delaminating? Original Holley stuff or cheap rebuild parts? I assume it had a fuel filter and no rotten line between the filter and the carb.

[4dblnkldude]

I'm not a carb guy by any means, I have a Holley on my 69. They hate to sit and I still have to clean go through it every two years minimum. The only thing I knew about q-jets until 4 months ago was the secondary bwaaaaahhh. I bought cliffs book and started to think...when I was a little younger I bought and sold alot of cars. Every time there was a q-jet on it, no matter how long it was sitting all it needed was fresh gas and a jump and started up.

[mgarblik]

The Quadra-jet carburetor is complicated compared to a Holley and it has more moving parts. (metering rods, choke pull-offs, air valves) The Holley modular carburetor is super simple and easy to work on with minimal skills and understanding of how the 6 circuits really work. That makes them a favorite of the weekend warrior who has a an old, abused, or worse previously messed-up quadrajet. With the two Doug Roe books, Cliff's book and his quality parts, the playing field has been leveled. Nothing on the street car gets more puzzled stares than a stock air cleaner with a Q-jet underneath, when it runs great like it should.

[Sirrotica]

Originally Posted by mgarblik

The Quadra-jet carburetor is complicated compared to a Holley and it has more moving parts. (metering rods, choke pull-offs, air valves) The Holley modular carburetor is super simple and easy to work on with minimal skills and understanding of how the 6 circuits really work. That makes them a favorite of the weekend warrior who has a an old, abused, or worse previously messed-up quadrajet. With the two Doug Roe books, Cliff's book and his quality parts, the playing field has been leveled. Nothing on the street car gets more puzzled stares than a stock air cleaner with a Q-jet underneath, when it runs great like it should.

LMAO,...... remembering the stares I got when I showed up at the dirt track with a 1969 Pontiac GP, with a T400 transmission (all dirt cars at that time had stick transmissions in them), 2 radiators (no one had ever seen a dirt car with 2 radiators either), and a Quadrajet carb on my race car. Every car in the pits had a holley carb on it. I was told more than once that if I really wanted to have a fast car I needed to put a holley on it......

I proved them wrong...…………

[JSchmitz]

Originally Posted by Sirrotica

I was told more than once that if I really wanted to have a fast car I needed to put a holley on it

I've heard that one a bunch also. Lol!

Although, I only switched from a 800 spreadbore double pumper, to a Q-jet, to be able to have better control of my launch at the track. My reaction, and 60', times got better after slowing down the secondaries.

i ran that Holley for MANY years without seeing the inside of it.

[Cliff R]

I have a couple of customers running well into the 9's in the 1/4 mile with Q-jets and Pontiac power. One of them has a very well set-up Quick Fuel carb available to him. It runs almost exactly the same ET/MPH as the Q-jet we did for him. He uses and prefers the Q-jet because it drives better back the return road and thru the pits, and much easier to come up on the converter when racing (foot braked). Otherwise he sees no advantages one of the other.......Cliff

[Sirrotica]

When I was confronted about why I was using a Q Jet (Quadrajunk was most commonly used term) instead of a holley, my reply was, "How much did you have in your holley carb"?

The usual reply back in the late 70s was at least $200. To which I said "I got this carb for free and I have about $25 invested in it as it sits". "When people start giving away holley carbs for what I have in mine I'll consider using one".…...……..NO REPLY...…………..