replacing rochester to edelbrock on 350
 

Hi Guys,

I have a rochester carb and thinking of replacing to edelbrock.
Can anyone tell me what edelbrock model is recomended to my 77 automatic 350 vette?
Do i need to replace the carb mount to do so?

Thanks, A.

You would need a 600 & another intake as there really is not enough room w/ adapter for a perf. setup. Al. intake & Holley rec.

I have a 1 " adapter under my Quad. with the dual snorkel intake on my 77. The air cleaner has a little less then a 1/4 " from hitting the hood. I also have a solid motor mount, so the motor does not move under acceleration.

So what, the adapter does not help stock auto. either! Closest point is at front of air cleaner.

An Edelbrock 1406 carb with an Edelbrock Performer EPS intake fit my 1979. I use a .2 Holley gasket between the carb and the stock dual snorkel air cleaner.Edelbrock claims that the EPS intake produces more power and torque than the Performer intake, and it is made for the Edelbrock carb so an adapter isn't needed between the two.

A change to an Edelbrock carb is not an upgrade in any sense of the word. Why do it?

springer89
Yes, the EPS intake is a good way for someone that wants to go square bore carb. w/ mild setup.

So you say. Everyone has a right to their say and beliefs, some people know their own motors and can hear/feel or see a difference.:thumbs:

I'm with "Mike" as go and change to an Edelbrock(Carter AFB upgrade), as know some here running well tuned Q-Jets willing to travel a bit to grab some easy street drag money. That's only if they slow down enough to actually have some idea where you are.

2Xs

Based on personal experience 3Xs

:iagree:

I've given them a few tries and never liked them. If you absolutely need to swap out the Qjet, get a spreadbore Holly

:iagree: Perhaps its my own ignorance but I have never had any luck tuning one a getting it to run correct.

:iagree::cheers::thumbs::leaving:

Its the opinion from just about everyone I know and not even a choice when getting a carb.
I like Holleys, I can make them work just fine.
I have a 600DP on mine now and it flat out rips!!!!
When I got the car I had to take it apart and clean it out and change the power valve that looked to be blown for a 100 years, added non stick gaskets and adjust the needle and now I don't touch it.

Why are you wanting to change the carb? What is the issue or symptom?

The same reason people use a K&N air filter, I think. Bragging rights and the perceived 5, 10, 20 HP gain on the butt dyno.

A well tuned Q-Jet (750 cfm) will shame an Edelbrock.

:iagree: I am right there with you on the Holley!:thumbs:

Thanks guys.
I believe some more clarifications will be in place here:
Have a 2601 edelbrock intake manifold with a stock, stutterer, nonfunctioning left Dizh, roachester carb. and need to replace or rebuild.
rather put in a new one.
considering putting an edelbrock to match the intake manifold.
can obtain a roachester with holley inside (first time i've heard about it. is that for real??) or a 1406 edelbrock.
can't get a holley here (Israel...).
my mechanic recomend the edelbrock over the roachester.
don't mind fuel economy, rather have more HP.
any sugestions?

With an Edelbrock carb you're likely to have less of both. The rochester with holley inside is just a q'jet rebuilt by Holley which they did for awhile if I'm not mistaken.

If you can get an edelbrock carb I dont see why a holley would be unavailable but you certainly would know better. I'd go with the holley rebuilt q-jet if my only choices were that or an edelbrock.

Holley makes a Q-J spread bore replacement carb.

Duals if stock exhaust...

I have to agree with the no Edel camp. If you can get that qjet working properly do so. I have a Holley 750 mech. dp and an Edel 750 mech. dp, a huge step down in power and mpg when running the Edel. I have to rebuild the Holley then back on it goes. What are these new Holleys like?

Do yourself a favor, buy a rebuild kit, a gallon of laquer thinner, a metal bucket and a non-plastic brush. Re-build the Q-jet (plenty of help here if you need it). Have the best carb and the satisfaction of knowing you did it yourself.

P.S. Never seek advice from that clown that recommended the Edelbroke carb again!

God bless, Sensei

I just picked up a slightly used Jet Stage 2 Q-Jet. Nice carb. Edelbrocks are OK; an old design (Carter AFB). Holleys are OK too, basically fuel dumpers that are good WOT. Q-Jets are the most complex carbs, and offer the best economy and power over the widest RPM / load range. This is because they are the most efficient. If you want the best street carb, you already have it.

I must just be lucky.

I have a light cam,ZZ4 heads Performer manifold, headers and dual exhaust. Engine had a nice lope at 700rpm but was running lean so it popped and hesitated.

Purchased a Edelbrock 1411.

The lope went away and the power was smooth through 6000rpm.
I also had an Edelbrock on a dodge 360 and it was a great combo.
They are easy to re-jet and are trouble free.

Holley always had power valve issues.
One back fire and they were toast.
I understand that is no longer an issue.
But the carter has always been a stable platform.
That's why Edelbrock choose it.

Can Q-jet out perform it, probably.
Will the carter give you less trouble? I think so.

Ralph

Thanks everyone.:thumbs:
Just found an importer that can bring a Holley from USA.:flag:
Can anyone give me Holley recomended part number (need a 600/ 650 cfm, electric choke, for 350 engine with edelbrock 2601 intake manifold with 4 bbl)?
A.

Edlebrock 1406... my best mod ever. Nothing beats the reliability of an electric choke.


Q-jet?:rofl: Give me a break.

If you are only interested in WOT power from a carb, you can take about any carb and set it up to perform equally between them...assuming that all have the capacity to satisfy your engine's needs. But, a carb is asked to do much more--like drive in-city traffic, idle well, be economical, etc, etc.

Holleys are good for WOT performance and simple adjustments/changes. Q-Jets are good performers, can idle smooth, transition from primaries to secondaries smoothly AND run more economically than any other 4-barrel carb design. Edelbrocks (old AFB design from the early 60's) are plentiful, relatively inexpensive and mediocre for everything else; they can be tuned for equal WOT performance, however.

If you don't like Q-Jets, are afraid of working on them, don't want to buy Cliff Ruggle's manual for rebuilding and tuning them (less than $20), and have lots of extra money for wasted fuel, spend another $300 for a new [old] AFB carb. Or, buy a $15 manual, a $30 rebuild kit, a $10 brass float and rebuild it yourself in one morning.

The choice is yours, of course....

I guess I have to apologize to the group.

I thought my Edelbrock ran pretty darn good.

Good idle good transition and better gas mileage.

I guess I just need more school n.

My Quadrajet has an electric choke. And it's 100 times better than your 1406. :D

There is nothing "wrong" with an Edelbrock carb (the Carter AFB design). Heck, Edelbrock made Q-Jets in the 80's and early 90's when GM quit making them. But, the AFB design is very 'basic' compared to more sophisticated carb designs.

For those that are "casual cruisers" driving their car once a week [or even less often] and not driving far, the need for a more complex carb isn't there...and it's not as important for having one that is economical, either. And, as I mentioned, the AFB can perform just as well as the others at WOT, if tuned properly. There is certainly no apology necessary for that.

We were just trying to supply the OP with more information about these carbs. His/her driving needs may be quite different from yours and it might be best to use a carb better suited to those needs. Your info and experience with the Edelbrock carb is just as valid as anyone else's. But, with more information, the poster can likely make the best choice for the needs of their car.

Some of us are a little more 'zealous' about Q-Jets because there are so many folks who give a 'bad rap' to it, strictly from lack of understanding. We would just like to provide a different perspective on the Q-Jet carb than what they've absorbed from 'folklore' over the years. I, for one, was not trying to "trash" the other carbs; each has its own merits. :thumbs:

I agree with 7T1 - Edelbrocks, Holleys and QuadraJets will all get the job done, especially at RPM and WOT. But for low end, driveability and gas milage a properly setup QJet is hard to beat. They are the most complex, which can be an issue for most. I, for one, would like to learn more; perhaps become a mini-guru. This is because I love our old cars.

So has any one here set up an Edelbrock on their engine.
I mean set it up not just bolted it on and then replaced it with a Q-jet
what was dialed in?

I'd like to hear this story.

Ralph

I have worked extensively with Holleys, Carters (Edelbrock), and Q-jets. As has been said here before, any can be set to give optimum WOT performance. They can also be tuned down to be more fuel efficient. But no other carb can match a Quadrajet for combining optimum fuel efficiency and WOT performance. They are not as simple to set up, but it is their complexity that makes them able to do what other carbs cannot.

Now I know there is always somebody who will say, "You can do the same thing with a Holley." Anyone who actually understands how the various carbs are designed and how they work know this is not true. No other carb can be as accurately tuned for optimum performance throughout the RMP range as a Quadrajet.

Now, If you have a dragster and fuel economy is not a concern, you just want to quickly tweek you mixture for the next run, trying to squeeze out that extra tenth, you can do that with a Holley in a fraction of the time it would take with a Q-jet. But for any street application, the Quadrajet is best, period. If you don't agree with that, you simply do not know your carbs (sorry).

God bless, Sensei

OKay

I saved the old Q-jet off my 1975 Corvette.
It was so lean at idle it loped.
It was so lean in transition the car bogged down and it popped back through the Carb.

When I put the 1411 on it all the bad went away, even the lope which I miss.

350 new rings and bearings, headers, performer manifold and ZZ4 heads and a Lunati cam.

Advertised Duration (Int/Exh): 262/268
Duration @ .050 (Int/Exh): 219/227
Gross Valve Lift (Int/Exh): .468/.489
LSA/ICL: 112/108
Valve Lash (Int/Exh): Hyd/Hyd
RPM Range: 1400-5800

So where do I start with my old Q-jet.

What jets, which kit where do I start?

Ralph

Same old stuff. If original to the car, must be better. Not always true. I ran a Q-jet (recently rebuilt) and an Edlebrock. Not even close. Edlebrock is a better Carb. More power. More reliable. Better gas mileage. I'd like see some factual evidence otherwise. Instead, the same "purists" repeating the same old stuff.

No one said anything about "being original to the car", Clubby99. And, since you didn't bring along any "facts"...other than what you have experienced...I guess you don't qualify as an expert, based on your own criteria. Have a nice day.

You are the one that claims to be the expert. Based on your past "purists" posts I doubt you ever ran any carb other than a Quadrajet. I ran both. That is the basis for my opinion. Do you have any independent performance data? Do you have any personal experience? I'd really like to know.

Yea , you ask 50 people if a Edelbrock carb is a good one and 49 to 1 says there junk.

I agree that a Q-jet if you can get it to run correctly is a pretty good carb. I am no expert on them since I ditched mine in 1983 (5 years old and 25,000 miles at the time) since it idled very rough (even after trying to adjust it), was hard starting when cold, stumbled on acceleration, and the mileage was atrocious (14 MPG at the time). Since then I have had the Holley 4175 650 CFM spreadbore Vacuum secondary carb and it has been flawless (just rebuilt in Dec 2010 after 25 years of use). The only change I made to the carb when it was new was put in the lightest secondary spring from the Holley spring pack. It starts easily, idles very smoothly (for an L-82), transitions seemlessly to the secondaries, and gets about 17-18 MPG at 65-70 MPH with 3.70 gears with the 4 speed if you drive real nice. It all depends what you want and have access to but the Q-jet can be a good carb but IMHO is overcomplicated for what a carb needs to do and my experience with the Holley 4175 has been really good-easy to tune, easy to rebuild, very good starting and running, good mileage, and seemless transition to power and WOT. just my 2 cents!

i agree i have an old swap meets Holley spreadbore on mine and love it. i bought it to be able to rebuild the quadrajet. i bought cliffs book and bought the complete kit from cliff and its bagged up and on the shelf because i have no desire to replace the Holley, best $20 swap meet part ever.

I just did the same on my 81. I had problems and returned the first
Edel, second one did the same thing. I called them and they said it sounds like a heat soak issue. put in a 160 degree stat SAT when it 90 + high humidity, drove about 15 miles no problems, drove to work today 22 miles no problems. I also ordered from Jegs a heat insulator gasket that replaces the carb gasket. Its a little thicker but I think it will still fit. I am going to put it on just for extra insurance.

The problem is often that too many people buy a carb and pop it on out of the box unmodified and this sets their impression of the carb in question. I have run all three of the carbs that have been discussed in this thread.

1>The original Qjet which was very old and never liked my new engine (carb unmodified from the L82 setup)
2>The Holley spreadbore which has been tuned by Lars and later (with new motor) tuned by Jeff Smith of Car Craft - it can get 22mpg on the freeway easy and runs smooth throughout all regimes.
3>Edelbrock emissions carb - which even with some tweaking ran awful.

I bought the edelbrock for emissions reasons and used it for smog tests, took it to a local corvette shop for smog testing and while they got the car passed, their opinion was - get rid of it and bring in the qjet - which they would fix and setup for the new motor.

I did this and the qjet - now properly setup runs as good or better than the holley, and vastly superior to the edelbrock in every respect. also the edelbrock doesnt have enough vacuum ports to hook up all the stupid vacc lines in an emissions setup - requiring additional tees in the lines to make it work.

That may or may not be an issue with some folks who arent worried about emissions testing.

In my experience, each of these carbs works of course, with all three set up for my engine, the Q-jet is slightly superior to the holley spreadbore, both of those are superior to the AFB.

Well said and always extremely useful when you can relate real world experience to your comments! I looked up your profile for your car (I knew it was not an original L-82 from prior conversations) when you stated the 22 MPG with the Q-jet since I was perplexed. My L-82 4 speed with 3.70 gears couldn't get 22 MPG if it was idling going downhill (LOL) with the Holley 650 spreadbore but does manage 17-18 MPG on the highway, if I drive 65-70MPH, no more than that-3,500 RPM. Sure enough, I see you have a TKO 5 speed which confirms my thoughts about the C3's gas mileage-If you want good mileage you MUST have an overdrive of some sort. I am pretty sure that my OEM L-82 with 3.70 gears and the 650 Holley could get very close to that 22 MPG if I installed a 5 speed with a steep overdrive. Full disclosure: Everything is original internally to the L-82 BUT the 4175 Holley, zero emissions, McJacks shorty headers, 2.5 inch true duals/Monza Turbo Mufflers, K&N airfilter in the OEM dual snorkel cold air intake, comp cams roller rockers, Crane HEI module/Crane adjustable vacuum advance, and a 170-175 operating temp.

Why do these discussions all get so heated?

The Q-Jet is a *great* carb. Being a spreadbore, it provides great off-idle and mid-range throttle response and fuel economy while giving great "oomph" when the secondaries open. Many are very tired, and many have been "tuned" such that they just don't work right any more. A professional rebuild followed with a professional tune will provide great results for even a pretty strong street engine. Finding a professional tuner can be a challenge, especially locally vs. mail order.

As for the aftermarket, it's a bit of a misnomer to compare a square bore to a spread bore carb as they're intended for different purposes. But having said that, I've used both the Performers and the Street Avengers and find that both work well...but I do find the Holley easier to tune. The Edelbrock is very convinient, but I typically can get closer with the Holley. I've been doing a lot more detailed performance tuning over the last year or so and that's kind of changed my opinion towards the Holley. That's just one guy's opinion and experience and means precisely dick :)

But all of these - working properly and tuned correctly - are going to be within a few percent of each other on power and will all offer good driveability and fuel economy.

Yes the car was originally an L-82 and that was what the q-jet was set up for until recently. Indeed the TKO assists in mileage though I did get as much as 20-21 mpg on the original L-82 4 speed setup, this however was on one tank all freeway long distance driving through fairly flat territory and was never repeated until I got the TKO - now 20-22 is commonplace on the freeway.

The Q-jet has always gotten better mileage than the holley.

Someone may find this interesting: Just pulled out the owners manual for my 78 L-82 4 speed and the original owner logged the cars gas mileage when it was fairly new (build date October 1977)-totally stock! No reference to the actual driving to get said mileage with the Q-jet-brand new. Here is what is in the operating record (he records miles and how many gallons and the PRICE for the fillup:

August 10, 1978-17.2 MPG
August 12, 1978-18.1
August 17, 1978-17.6
August 21, 1978-16.1
September 17, 1978-16.2

Not too shabby with the Q-Jet for probably mixed driving, a little better than the Holley 4175 Spreadbore, but not by much-maybe 1-1.5 MPG.

If this is a serious request and you have the patience and want to dig in and learn and do the work yourself, PM me and I will walk you through.

God bless, Sensei

The 75 is the worst of all the qjets, a 1 year only design. It was the first attempt at the super lean carbs and was immediately abandoned that same year. They can run very well and extremely lean on a stock engine, but do yourself a favor and get a 76+up carb to get a lot more tuneability and potential.

Here's what author Cliff Ruggles said about the Edelbrock carb in another forum.

Much of the problem is that many owners don't know how to tune a Carb properly. They bolt it on and that's it. Of course the carb will run but not at peak performance and best gas mileage. Then the owner is disappointed with their "bad" new carb. I'm not sure which Carb is the best. I'd like to know. I'm tired of hearing everyone state their carb is the best. Has anyone ever seen any independent test data? Maybe a magazine review by an expert?

Maybe a better "expert" than Cliff Ruggles. Duh, even I know a 750 carb is wrong for a 350. Should use a 600 carb. Another example of an "expert" not giving good advice.

While from a strict size perspective that might be true, with a vacuum-secondary carb it's tough to over-carb. With a square-bore, it's more of an issue since the primaries are too big and mixture velocity is lost, but with a spread-bore like the Q-Jet the small primaries give good throttle response and the huge secondaries will only open as much as they're needed - especially if the air valve is adjusted correctly.