Need a new carb -- suggestions?

[caffeineaholic]

Hi all,

I found out that I need a new carb for my 305 (the air horn is warped quite badly). I wanted some opinions and input before getting one in the near future. I want something that can deliver the performance I got with my Quadrajet (when it was working right) and also similar fuel economy. Also, something that can still work great for a 350 (which I plan to put in my Caprice by the end of this year).

Also, it would be great if I had the option to add slight upgrades to it in the future (such as bigger metering rods? -- Not quite sure what an upgrade would be to deliver more fuel).

My mechanic suggested an Edelbrock but I also hear that Holley's are great. -- Or should I get another Quadrajet or other brand?

I would like to get something in the mid-range of performance and cost so that it can accommodate any future upgrades (such as a better performing intake manifold, better headers, etc).

Thanks for your input!

[Blt2Lst]

Originally Posted by caffeineaholic

Hi all,

I found out that I need a new carb for my 305 (the air horn is warped quite badly). I wanted some opinions and input before getting one in the near future. I want something that can deliver the performance I got with my Quadrajet (when it was working right) and also similar fuel economy. Also, something that can still work great for a 350 (which I plan to put in my Caprice by the end of this year).

Also, it would be great if I had the option to add slight upgrades to it in the future (such as bigger metering rods? -- Not quite sure what an upgrade would be to deliver more fuel).

My mechanic suggested an Edelbrock but I also hear that Holley's are great. -- Or should I get another Quadrajet or other brand?

I would like to get something in the mid-range of performance and cost so that it can accommodate any future upgrades (such as a better performing intake manifold, better headers, etc).

Thanks for your input!

You can get replacement air horns for the q-jet, I had to replace mine when I had mine rebuilt, the cost was an additional $30.

For a stock 305, the q-jet is probably the way to go for economy and performance. Getting yours rebuilt will be the less expensive option.

Holley also makes a spread bore carb similar in design to the q-jet but it will cost you close to $400.

If you do not have to pass emissions, Edelbrock is a good carb with lots of adjustability and from my experience, they run good out of the box, at least mine did when I put one on my 57 chevy with a 283ci.
If using the Edelbrock carb, you will also need a adapter plate because of the square bore design mating up to a spread bore intake.

[caffeineaholic]

Yeah, I've been looking online at both Holley and Edelbrock and I can't find any carbs that allow me to hook up a M/C solenoid -- if I am unable to hook that up the CEL should come on unless if I am mistaken.

Am I correct in thinking that if I choose to not go with a rebuild or a remanufactured Q-jet but with another carb that I will have computer problems? -- Also what about the Idle Speed Control servo? This may also make the CEL come on I think.

I've heard that the Q-Jet I have (E4ME) can deliver 750+CFM -- so is it best just to rebuild or get a new one? Is this a realistic number -- the CFM? Or perhaps it can deliver that but cannot deliver enough fuel without modification?

Lastly, I'd like to avoid an adapter plate -- I've head that it's best to not use one if possible (I guess a minor performance decrease of some kind?)

[Blt2Lst]

Originally Posted by caffeineaholic

Yeah, I've been looking online at both Holley and Edelbrock and I can't find any carbs that allow me to hook up a M/C solenoid -- if I am unable to hook that up the CEL should come on unless if I am mistaken.

Am I correct in thinking that if I choose to not go with a rebuild or a remanufactured Q-jet but with another carb that I will have computer problems? -- Also what about the Idle Speed Control servo? This may also make the CEL come on I think.

I've heard that the Q-Jet I have (E4ME) can deliver 750+CFM -- so is it best just to rebuild or get a new one? Is this a realistic number -- the CFM? Or perhaps it can deliver that but cannot deliver enough fuel without modification?

Lastly, I'd like to avoid an adapter plate -- I've head that it's best to not use one if possible (I guess a minor performance decrease of some kind?)

If you want to keep your car emissions compliant, you are pretty much stuck with using the electronic q-jet that came on the car.
I would have yours rebuilt, when you get it back it should work like a new one.

These guys are the q-jet experts
They offer rebuilt or new.

http://www.smicarburetor.com/product...D2/86/sfID3/34

[j cAT]

Originally Posted by caffeineaholic

Yeah, I've been looking online at both Holley and Edelbrock and I can't find any carbs that allow me to hook up a M/C solenoid -- if I am unable to hook that up the CEL should come on unless if I am mistaken.

Am I correct in thinking that if I choose to not go with a rebuild or a remanufactured Q-jet but with another carb that I will have computer problems? -- Also what about the Idle Speed Control servo? This may also make the CEL come on I think.

I've heard that the Q-Jet I have (E4ME) can deliver 750+CFM -- so is it best just to rebuild or get a new one? Is this a realistic number -- the CFM? Or perhaps it can deliver that but cannot deliver enough fuel without modification? Lastly, I'd like to avoid an adapter plate -- I've head that it's best to not use one if possible (I guess a minor performance decrease of some kind?)

you can buy quadrajet carb for your vehicle with CFM'S up to 900....this is available as I was searching a few months ago for what q jets were available...with a 305 cu 650 cfm is about it ..305 is not an engine to be modified to get any more power ...designed not for any more ...intake ports toooo small........

you should be able to get something to work from a scrap yard to repair your carb issue...

after you get your 350cu then with that engine you can determine the correct carb CFM to use with that engine..

[Blt2Lst]

Even if your stock 305 was turning 5000 rpms, it would not need anywhere close to 750 cfm of airflow. Probably even less than 600 cfm at that rpm.
I would guess that that is why the secondaries do not open fully unless modified to do so on the stock q-jet.

Don't worry about the airflow so much, just do your rebuild on your stock carb and move on.

[mike561]

Dont mean to hijack your thread but whats the best way to get the most performance out of a stock q-jet for a 305? are there any mods that can be done to the carb itself?

[caffeineaholic]

Thanks for all of your input, I will consider a carb rebuild because I would like for everything to stay emissions compliant for the time being. I have looked at my local junk yards before and I actually have extreme difficult finding E4ME carbs -- usually only the older ones (no M/C solenoid) are available.

And don't worry mike561 I don't think it's a big deal -- I'm also interested in what can be done to improve the Q-Jet's performance (most especially for when I obtain a 350).

[Blt2Lst]

Originally Posted by mike561

Dont mean to hijack your thread but whats the best way to get the most performance out of a stock q-jet for a 305? are there any mods that can be done to the carb itself?

Check out the link to SMI Carbs above and look at the stage 1 rebuild details.
It lists the upgrades they do that are emissions legal.
It's basically, high flow needle and seat, different secondary metering rods and high capacity accelerator pump for the performance part of the rebuild.

When I got my carb back for them, I could really feel the difference at WOT.

[caffeineaholic]

Originally Posted by Blt2Lst

Check out the link to SMI Carbs above and look at the stage 1 rebuild details.
It lists the upgrades they do that are emissions legal.
It's basically, high flow needle and seat, different secondary metering rods and high capacity accelerator pump for the performance part of the rebuild.

When I got my carb back for them, I could really feel the difference at WOT.

Very cool, I'll consider them. You also mentioned that it was only an extra 30$ for a new air horn for it? Is that all? Sounds like a great deal.

If there are other problems with the carb will they charge me for replacing any other parts without first letting me know? (I'm worried about paying up to 300$ for a rebuild and then being charged 350$ or more without any notice)...

Also, is there a noticeable difference in the MPG you got after those enhancements? Or is it just negligible?

[silicon212]

caffeineaholic -

There are LOTS of junkyards around the valley that could have this carb - I've had no problems whatsoever sourcing them from Ecology on 27th ave/Lincoln or west Broadway, pick'n'pull on 56th st between Chandler and Ray, Pick-a-part various locations or otherwise.

I've picked up 10 or so over the years ... never had a problem getting one when it was needed.

[Blt2Lst]

Originally Posted by caffeineaholic

Very cool, I'll consider them. You also mentioned that it was only an extra 30$ for a new air horn for it? Is that all? Sounds like a great deal.

If there are other problems with the carb will they charge me for replacing any other parts without first letting me know? (I'm worried about paying up to 300$ for a rebuild and then being charged 350$ or more without any notice)...

Also, is there a noticeable difference in the MPG you got after those enhancements? Or is it just negligible?

Mine also needed a TPS, that was another $30.

If yours needs a MC solenoid or TPS, that would be additional. You also will have shipping costs involved.
Just give them a call, Sean will answer all your questions.


There was a increase in mpg, I don't have any numbers on that yet but it seems to be using less gas overall.

[caffeineaholic]

Originally Posted by silicon212

caffeineaholic -

There are LOTS of junkyards around the valley that could have this carb - I've had no problems whatsoever sourcing them from Ecology on 27th ave/Lincoln or west Broadway, pick'n'pull on 56th st between Chandler and Ray, Pick-a-part various locations or otherwise.

I've picked up 10 or so over the years ... never had a problem getting one when it was needed.

Maybe I've just had bad luck the last few times I went to Pick-a-Part East and West. I typically find non-electric Q-Jets. Some will have an electric choke, but then be missing the M/C solenoid and/or ISC servo. However, I'll give Ecology and Pick'n'Pull a try.

Blt2Lst, I will also give them a call in the near future and get a quote.

Thanks.