what carb is better and why - The 1947 - Present Chevrolet & GMC Truck Message Board Network

RANDAL · 03-13-2013, 06:33 PM

Hi guys quick question I have a edelbrock carb on the jimmy now and was thinking about changing it to a quadrajet. I dont know anything about carbs so not sure which is better. My edelbrock is electric choke and thats all I know about it, will look to see which one I have. I do know I need to rebuild it as it cuts out a little on me when I give it gas. I get 8 to 15 mpg's with the edelbrock depending on how I drive it. question is what do you guys prefer and why likes and dis likes. I drive it mainly around town and on weekends I drive it highway and mountains

Thanks

robs71k5 · 03-13-2013, 08:33 PM

I'm in the same boat as you. I have an edlebrock thats leaking out the side and the other one is two rich running so I decided if I have to rebuild a carb then might as well build the one that came with it .Then found out it didnt have an electric choke on it and I didnt want to change to intake maniifold so that left me with a quadrajet M4MC wich is a modified carb which houses an electric and vacume operated choke on the same carb.
So there you have it.
If you have the origional cast iron intake manifoldf then you should be able to rebuild the carb with out the electric choke in liu of the vacume opperated one

RANDAL · 03-13-2013, 08:37 PM

Quote:

Originally Posted by robs71k5

I'm in the same boat as you. I have an edlebrock thats leaking out the side and the other one is two rich running so I decided if I have to rebuild a carb then might as well build the one that came with it .Then found out it didnt have an electric choke on it and I didnt want to change to intake maniifold so that left me with a quadrajet M4MC wich is a modified carb which houses an electric and vacume operated choke on the same carb.
So there you have it.
If you have the origional cast iron intake manifoldf then you should be able to rebuild the carb with out the electric choke in liu of the vacume opperated one

Yeah I'm not sure what manifold I have and I would like to have an electric choke but really doesn't matter I will look tonight to see what I have.

Thanks

POS1 · 03-13-2013, 10:54 PM

All the old Chevy mechanics I know (a lot of them, btw, bc I'm in the parts biz) all call the Edelbrocks crap the Quadrajets wonderful. My 71 came with an Edelbrock and its a temperamental bastard - long cold starts, idle issues. I've been told over and over that the QJ won't have that finickyness. I'll be swapping over soon.
Posted via Mobile Device

SlammedBlazerLife · 03-13-2013, 10:58 PM

I have an Edlebrock carb on my 72' Blazer and it does alright on flat surfaces, But soon as i take it 4 wheeling at steep angles it cuts out and leaks fuel from the carb at steep angles. I'm really tired of the bad performance this carb gives me when i'm on the trail or rock crawling. I have been told that Holley has a 4x4 specific carb. But I Have heard pros and cons from local experienced 4 wheelers for the holley 4x4 carb. We need a great carb for our blazers any body know of one or recommendations???

**truckster** · 03-13-2013, 11:06 PM

The Quadrajet you want is a model 4ME or M4ME; the E designates electric choke. Model 4M4C is a hot-air choke. The M prior to the 4 shows it as a "modified" Quadrajet; those had thicker castings.

Any spread-bore manifold (factory or aftermarket designed for a Quadrajet) will work with any of the Quadrajets mentioned.

The Quadrajet is, in my opinion, the best carburetor available. Cliff Ruggles has an excellent book on building and tuning the Quadrajet called How to Rebuild and Modify Rochester Quadrajet Carburetors.

robs71k5 · 03-14-2013, 01:50 AM

Truckster I hope your certain cause it I thought the "E" stands for electonic carb and that carb started coming in 1980"s. I guess I have to go back and look at the rebuild sites to get explanations again .

robs71k5 · 03-14-2013, 02:04 AM

My Bad : Truckster is Correct it is a M4ME Here is a qick video to sum it up. Thanks Truckster for pointing that out !

Decoding a Rochester Quadrajet part 1: The name -...

**pound41** · 03-14-2013, 09:05 AM

I have a an electric choke conversion on my stock carb. mounts in same place run the wire for power and ground on a manifold bolt. had it for 15 years works great

in deep 72 · 03-14-2013, 09:47 AM

I think the Qjet is a love it or hate it carb. I've never had good luck trying to rebuild them...my dad on the other hand is a master. He put one on his '65 chevelle 327. Dyno'd at 340 hp and got better than 20 mpg. I was going to go with one on my '72 Blazer, but needed something bigger than a Qjet (running a 468BB) so went with Edlebrock. Not very impressed with it. Might have to try my hand at rebuilding the Holly that came on it.

99-LS1-SS · 03-14-2013, 10:08 AM

The quadrajet is the way to go if it has been rebuilt properly. It is a great all around carb because of the small primaries and the large secondaries. If you want to cruise around town and not burn through an entire tank of gas you can just keep your foot out of it. If you want to play the secondaries will do the trick.

**truckster** · 03-14-2013, 10:17 AM

Quote:

Originally Posted by pound41

I have a an electric choke conversion on my stock carb. mounts in same place run the wire for power and ground on a manifold bolt. had it for 15 years works great

That will work with any Quadrajet that has an integrated hot air choke. You just need to get the coil; you can probably pick one up at a wrecking yard. Remove the paper gasket between the coil cover and the carb so it will ground. I've never seen a conversion of a divorced choke (choke coil on the manifold) to an electric choke; it might be possible, but I've never seen it done.

The electronic Quadrajet has an E at the beginning: E4M. It's easy to spot because it's the only Quadrajet that has an electrical connector on the top of the fuel bowl.

jaros44sr · 03-14-2013, 10:31 AM

You can always put a fuel pressure regulator on it, dial it down to 4psi. Should help with the steep angles somewhat....

fxdxharley · 03-14-2013, 11:08 AM

I had a edelbrock on my last truck and it was easy to tune but required almost daily adjustments on the air screws. good for the street but not for wheeling. the Quadrajet is much better for offroad. their not prone to bogging on steep hills and off cambers. i rebuilt one probably 20 yrs ago and ran it before the eldelbrock, i liked it.

**pound41** · 03-14-2013, 12:49 PM

http://www.ebay.com/itm/Carburetor-E...355?pt=Motors_
Not sure if you can click on the link I provided or not. It has a good picture of it installed. There are several people selling them on ebay. Range $40-60 I got my first many years ago from JC Whitney. for $ 8 worked so good I bought several just to have. I was having trouble with the spring in my choke and had tried several others when my Dad told me to get the conversion

**72 paul** · 03-14-2013, 01:02 PM

how bout holly 670 truck avenger, anybody running. hear there not highway friendly. got one but not useing yet.

RANDAL · 03-14-2013, 02:56 PM

Quote:

Originally Posted by truckster

The Quadrajet you want is a model 4ME or M4ME; the E designates electric choke. Model 4M4C is a hot-air choke. The M prior to the 4 shows it as a "modified" Quadrajet; those had thicker castings.

Any spread-bore manifold (factory or aftermarket designed for a Quadrajet) will work with any of the Quadrajets mentioned.

The Quadrajet is, in my opinion, the best carburetor available. Cliff Ruggles has an excellent book on building and tuning the Quadrajet called How to Rebuild and Modify Rochester Quadrajet Carburetors.

Thank you truckster this helps alot. also will be buying one used or junkyard what years of cars and trucks will I need to look for.

RANDAL · 03-14-2013, 02:59 PM

Thank you all for your help, I really appreciate your feed back. I have decided to go with a Quadrajet.

Ole Beater · 03-14-2013, 04:52 PM

Everyone i talk to with an edelbrock has an off idle hesitation. I have tried 2 different carbs with the same problem. They do have an offroad kit for the floats that helps out. I ran a quadrajet off road that could handle the hills a lot better than the edelbrock. The problem iwth quadajets is the shafts wear out if they are old and let air leak past making it hard to tune. They need to be rebushed around the butterfly shafts. Overall i would go with a q-jet. Another thing to look for is that they come in 2 different sizes, but i cant remember what that is. I think one was a 700+ cfm and the other 800+ for the big block cars. You can tell by measuring the bores.

RANDAL · 03-14-2013, 04:58 PM

Quote:

Originally Posted by Ole Beater

Everyone i talk to with an edelbrock has an off idle hesitation. I have tried 2 different carbs with the same problem. They do have an offroad kit for the floats that helps out. I ran a quadrajet off road that could handle the hills a lot better than the edelbrock. The problem iwth quadajets is the shafts wear out if they are old and let air leak past making it hard to tune. They need to be rebushed around the butterfly shafts. Overall i would go with a q-jet. Another thing to look for is that they come in 2 different sizes, but i cant remember what that is. I think one was a 700+ cfm and the other 800+ for the big block cars. You can tell by measuring the bores.

Yeah mine kinda hesitates a bit when I hit the gas and thanks for your help

in deep 72 · 03-14-2013, 07:54 PM

Qjet came in 750 CFM and 800 CFM. The 800 came on the Pontiac 455. After seeing what they aree capible of, I'm a Qjet fan and think you've made the right choice going that route. Just wish I could find one a little bigger so I could also.

aldtime · 03-14-2013, 09:38 PM

Saw this thread and thought I'd put my 2 cents...My blazer came with an edelbrock when I bought it and one of the first things I found out was that the carb would flood and/or empty and stall the motor when getting bouncy while 4-wheelin. Installed spring loaded needles and seats and that fixed the prob. Didn't have the stalling issue since...

fatgump · 03-14-2013, 10:01 PM

Here is what my Edelbrock AVS 650 did before a float adjustment.

Gump's truck at the 2013 Goodguys Spring...

markedgar5 · 06-02-2013, 02:11 AM

If goal is increased mpg? Would the qjet be the way to go?
Posted via Mobile Device

mud.man.rj · 06-02-2013, 02:43 AM

The q jet has smaller primarys so will get better fuel mileage but the Edelbrock will have better power (torque) on bottom end, only thing is most Edelbrocks have the square flange same as a Holley so the Q jet won't bolt on the intake without a carb adapter plate, which is fine but more money. I work on "all" carbs and prefer the Edelbrock because of more torque but prob 1-2 mpg less fuel economy, I find them the simplest carb to work on, question is why not find someone knowledgeable to have a look at your Edelbrock first, may only be a simple accelerator pump adjustment, as in richer to clear it up. Worth a shot.

03-13-2013, 06:33 PM	#1
RANDAL Registered User Join Date: Jun 2012 Location: SALT LAKE CITY, UTAH Posts: 396	what carb is better and why Hi guys quick question I have a edelbrock carb on the jimmy now and was thinking about changing it to a quadrajet. I dont know anything about carbs so not sure which is better. My edelbrock is electric choke and thats all I know about it, will look to see which one I have. I do know I need to rebuild it as it cuts out a little on me when I give it gas. I get 8 to 15 mpg's with the edelbrock depending on how I drive it. question is what do you guys prefer and why likes and dis likes. I drive it mainly around town and on weekends I drive it highway and mountains Thanks

03-13-2013, 08:33 PM	#2
robs71k5 K5drive Join Date: Nov 2004 Location: burnaby BC Canada Posts: 809	Re: what carb is better and why I'm in the same boat as you. I have an edlebrock thats leaking out the side and the other one is two rich running so I decided if I have to rebuild a carb then might as well build the one that came with it .Then found out it didnt have an electric choke on it and I didnt want to change to intake maniifold so that left me with a quadrajet M4MC wich is a modified carb which houses an electric and vacume operated choke on the same carb. So there you have it. If you have the origional cast iron intake manifoldf then you should be able to rebuild the carb with out the electric choke in liu of the vacume opperated one

03-13-2013, 10:54 PM	#4
POS1 Registered User Join Date: Jul 2011 Location: Houston, Texas Posts: 145	Re: what carb is better and why All the old Chevy mechanics I know (a lot of them, btw, bc I'm in the parts biz) all call the Edelbrocks crap the Quadrajets wonderful. My 71 came with an Edelbrock and its a temperamental bastard - long cold starts, idle issues. I've been told over and over that the QJ won't have that finickyness. I'll be swapping over soon. Posted via Mobile Device __________________ - Brian FleetFilter.com 1991 Chevrolet V1500 Suburban 4x4 1986 Jeep CJ7 1969 Porsche 911S Targa

03-13-2013, 10:58 PM	#5
SlammedBlazerLife Registered User Join Date: Mar 2013 Location: Durango,co Posts: 28	Re: what carb is better and why I have an Edlebrock carb on my 72' Blazer and it does alright on flat surfaces, But soon as i take it 4 wheeling at steep angles it cuts out and leaks fuel from the carb at steep angles. I'm really tired of the bad performance this carb gives me when i'm on the trail or rock crawling. I have been told that Holley has a 4x4 specific carb. But I Have heard pros and cons from local experienced 4 wheelers for the holley 4x4 carb. We need a great carb for our blazers any body know of one or recommendations???

03-13-2013, 11:06 PM	#6
truckster Senior Member Join Date: Jan 2001 Location: Orem, Utah Posts: 7,854	Re: what carb is better and why The Quadrajet you want is a model 4ME or M4ME; the E designates electric choke. Model 4M4C is a hot-air choke. The M prior to the 4 shows it as a "modified" Quadrajet; those had thicker castings. Any spread-bore manifold (factory or aftermarket designed for a Quadrajet) will work with any of the Quadrajets mentioned. The Quadrajet is, in my opinion, the best carburetor available. Cliff Ruggles has an excellent book on building and tuning the Quadrajet called How to Rebuild and Modify Rochester Quadrajet Carburetors.

03-14-2013, 01:50 AM	#7
robs71k5 K5drive Join Date: Nov 2004 Location: burnaby BC Canada Posts: 809	Re: what carb is better and why Truckster I hope your certain cause it I thought the "E" stands for electonic carb and that carb started coming in 1980"s. I guess I have to go back and look at the rebuild sites to get explanations again .

03-14-2013, 09:05 AM	#9
pound41 Registered User Join Date: Dec 2002 Location: Northern Virginia Posts: 1,269	Re: what carb is better and why I have a an electric choke conversion on my stock carb. mounts in same place run the wire for power and ground on a manifold bolt. had it for 15 years works great

03-14-2013, 09:47 AM	#10
in deep 72 Registered User Join Date: Jul 2012 Location: Lisbon ND Posts: 111	Re: what carb is better and why I think the Qjet is a love it or hate it carb. I've never had good luck trying to rebuild them...my dad on the other hand is a master. He put one on his '65 chevelle 327. Dyno'd at 340 hp and got better than 20 mpg. I was going to go with one on my '72 Blazer, but needed something bigger than a Qjet (running a 468BB) so went with Edlebrock. Not very impressed with it. Might have to try my hand at rebuilding the Holly that came on it.

03-14-2013, 10:08 AM	#11
99-LS1-SS Registered User Join Date: Mar 2011 Location: Oak Ridge NC Posts: 957	Re: what carb is better and why The quadrajet is the way to go if it has been rebuilt properly. It is a great all around carb because of the small primaries and the large secondaries. If you want to cruise around town and not burn through an entire tank of gas you can just keep your foot out of it. If you want to play the secondaries will do the trick. __________________ My 1972 2WD Blazer build 1984 K10 beater truck

03-14-2013, 10:31 AM	#13
jaros44sr Registered User Join Date: May 2006 Location: Philadelphia, Pa. 19454 Posts: 9,452	Re: what carb is better and why You can always put a fuel pressure regulator on it, dial it down to 4psi. Should help with the steep angles somewhat.... __________________ Semper Fi...Uncle Sam, you da man All parts offered to help are free, unless otherwise noted Dont try this stuff in my build thread, unless you have 55 years of mechanical OTJ training SAFETY FIRST AS usual, off topic They say your mind goes second, can't remember the first Jim

03-14-2013, 11:08 AM	#14
fxdxharley Just a nother gear head Join Date: Jul 2009 Location: Barrington NH Posts: 501	Re: what carb is better and why I had a edelbrock on my last truck and it was easy to tune but required almost daily adjustments on the air screws. good for the street but not for wheeling. the Quadrajet is much better for offroad. their not prone to bogging on steep hills and off cambers. i rebuilt one probably 20 yrs ago and ran it before the eldelbrock, i liked it. __________________ 2013 HD FLHX 2000 chevy 2500 6.0l 4x4 3dr 2000 harley fxdx 71 Jimmy 4x4- future crawler/ woods rig 71 blazer (C4 2wd conv project) http://67-72chevytrucks.com/vboard/s...d.php?t=523589

03-14-2013, 12:49 PM	#15
pound41 Registered User Join Date: Dec 2002 Location: Northern Virginia Posts: 1,269	Re: what carb is better and why http://www.ebay.com/itm/Carburetor-E...355?pt=Motors_ Not sure if you can click on the link I provided or not. It has a good picture of it installed. There are several people selling them on ebay. Range $40-60 I got my first many years ago from JC Whitney. for $ 8 worked so good I bought several just to have. I was having trouble with the spring in my choke and had tried several others when my Dad told me to get the conversion

03-14-2013, 01:02 PM	#16
72 paul Senior Member Join Date: May 2011 Location: las vegas'nv Posts: 493	Re: what carb is better and why how bout holly 670 truck avenger, anybody running. hear there not highway friendly. got one but not useing yet.

03-14-2013, 02:59 PM	#18
RANDAL Registered User Join Date: Jun 2012 Location: SALT LAKE CITY, UTAH Posts: 396	Re: what carb is better and why Thank you all for your help, I really appreciate your feed back. I have decided to go with a Quadrajet.

03-14-2013, 04:52 PM	#19
Ole Beater Registered User Join Date: Oct 2011 Location: St Petersburg, Florida Posts: 154	Re: what carb is better and why Everyone i talk to with an edelbrock has an off idle hesitation. I have tried 2 different carbs with the same problem. They do have an offroad kit for the floats that helps out. I ran a quadrajet off road that could handle the hills a lot better than the edelbrock. The problem iwth quadajets is the shafts wear out if they are old and let air leak past making it hard to tune. They need to be rebushed around the butterfly shafts. Overall i would go with a q-jet. Another thing to look for is that they come in 2 different sizes, but i cant remember what that is. I think one was a 700+ cfm and the other 800+ for the big block cars. You can tell by measuring the bores.



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03-14-2013, 07:54 PM	#21
in deep 72 Registered User Join Date: Jul 2012 Location: Lisbon ND Posts: 111	Re: what carb is better and why Qjet came in 750 CFM and 800 CFM. The 800 came on the Pontiac 455. After seeing what they aree capible of, I'm a Qjet fan and think you've made the right choice going that route. Just wish I could find one a little bigger so I could also.

03-14-2013, 09:38 PM	#22
aldtime Registered User Join Date: Mar 2011 Location: Albuquerque NM Posts: 15	Re: what carb is better and why Saw this thread and thought I'd put my 2 cents...My blazer came with an edelbrock when I bought it and one of the first things I found out was that the carb would flood and/or empty and stall the motor when getting bouncy while 4-wheelin. Installed spring loaded needles and seats and that fixed the prob. Didn't have the stalling issue since...

06-02-2013, 02:11 AM	#24
markedgar5 Registered User Join Date: Nov 2003 Location: Kresgeville PA Posts: 110	Re: what carb is better and why If goal is increased mpg? Would the qjet be the way to go? Posted via Mobile Device

06-02-2013, 02:43 AM	#25
mud.man.rj Registered User Join Date: Dec 2011 Location: Creighton Sask. Canada Posts: 4,121	Re: what carb is better and why The q jet has smaller primarys so will get better fuel mileage but the Edelbrock will have better power (torque) on bottom end, only thing is most Edelbrocks have the square flange same as a Holley so the Q jet won't bolt on the intake without a carb adapter plate, which is fine but more money. I work on "all" carbs and prefer the Edelbrock because of more torque but prob 1-2 mpg less fuel economy, I find them the simplest carb to work on, question is why not find someone knowledgeable to have a look at your Edelbrock first, may only be a simple accelerator pump adjustment, as in richer to clear it up. Worth a shot.

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