Wamplet

Problem: My carburetor is in need of replacement. The car starts up really hard. I have to hold the pedal all the way down to the floorboard and then turn the key. Then I have to keep it revving a bit to keep it from dying, for about a minute or so. Then it's fine.

I have a 1974 L48 350.

I think the previous owner installed a Carter AFB in it, but I believe the Rochester 4MV is the stock carburetor.

Well, anyways, my question is this:

My mechanic suggested that I get a carburetor with an electrical choke so it starts up better. He said he would leave it the way it is, with a hot air choke, but he said if I wanted to, I could get a carburetor with an electric choke and he would do the rest to install it and the wires for free.

I am looking through an Edelbrock Catalog at the carburetors and made a list of some of the things in there:

#1407
750cfm Performer Manual choke Carburetor.

#1478
Electric Choke Kit for #1407 carb.

It mentions possibly using a carb stud, nut, and washer kit:

#8008
5/16"-18X1-3/8"
or
#8024
5/16"-18X1-3/4"
If I need this, what measurements might i need to make? Where do I get them from, rather?


#7118
Performer RPM LS1 Manifold

#4807
160 degree LS1 thermostat Assembly for #7118 Manifold
or
#4808
180 degree LS1 thermostat Assembly for #7118 Manifold


The list goes on and on.

Well, my first main question would be, is that carburetor compatible with the stock engine/manifold?

Also, do I need the other parts listed after that? I see the catalog mentions several related items and I put them in here for good measure, but am really hoping that someone might be able to tell me that the carburetor and the electrical choke kit might be all I need.

I am not sure if I need a new manifold (and other parts) for the carburetor or if I can just use my existing manifold for it to work. :o I'd prefer to just find a way to order a good carburetor and not have to buy extra stuff to make it fit/work. I don't mind it if it's the only route, but I'm hoping there is another less expensive way. I'd hate to get all that, especially for a stock engine. I'd rather wait a while down the road and possibly drop a bigger engine in it and then waste all that money on everything.

Unfortunately, I'm not really that technical when it comes to cars and I'd really appreciate any help on what I should do.

I don't get to post too much, but I've recently registered and love reading the threads daily.

Other brand suggestions are welcomed. I just happened to have an Edelbrock catalog, so that was all I had to work with.

Thanks again for your time in reading this.


[Modified by Wamplet, 9:40 PM 6/19/2004]

page62

Okay. First, you need to check and see what kind of intake manifold your engine has. If it's the stock manifold, you'll likely see "GM" and the firing order. Edelbrocks will say...well, you know. Let us know what you have...it can influence what you should buy.

Next, a 750 cfm carb is way too big for your application. Think 600 cfm. You can buy an carb with an electric choke already on it. The Edelbrock 1406 would be perfect for your application.

I'm not sure why you're looking at LS1 thermostat housings, they have NOTHING to do with what you need.

Finally, what can't your "mechanic" rebuild your carb and install an electric choke on it? It would save you lots of money! Check the yellow pages for a carburetor shop...there are still a few around.

Wamplet

Ok, I just went out to check. The manifold is painted Reddish-Orange and has "GM" stamped on it.

After I posted this thread, I was looking some more and saw the 600cfm with the electric choke. I wasn't really too sure what cfm number I am supposed to be looking at. :o


He did or tried, at any rate. He said went through 3 rebuild kits from AutoZone and 2 from Hi-Lo or whatever their equivalent is around here. He said they were not working and kept taking the kits back. I'm not sure if he installed each one or just opened them up, but he said the kits they had were worse than what I currently had on there. Plus, I think the carburetor not being a stock carburetor may have been part of the problem as well. :o

I really appreciate your response and hope to see more. If you need anymore info, let me know.

I was thinking of getting an air cleaner, and valve covers as well. I'm not sure if that will factor in to this or not. Although, my main priority is to get the carburetor replaced with a new one. Just not quite sure what exactly else I might need to go with the 600cfm.

page62

The Edelbrock 1406 is a direct replacement for a Carter AFB. Make sure that's what you've got and stick it on there! Eventually, you may want to replace the intake manifold, but you can do that as your budget allows.

Wamplet

Ok, I feel like quite the dufus. : :o

I removed the air cleaner and got a closer look at the carburetor and it said Rochester QuadraJet. :o

I noticed in the catalog there were "Quadrajet" carburetors ( numbers #1901, 2,3,4,10) However, only one of them appears to be an electric choke carb and it says it's for trucks #1906 ( big blocks, I assume, since it said 454). Plus they are too high in the cfm number, All 795 to 800. There was also a #1904 with electric choke, which said it was for trucks, but then I looked it up in a compatiblity chart in the catalog and it said for 1980 Chevy cars.



[Modified by Wamplet, 1:20 AM 6/20/2004]

page62

That changes everything! Send your carb to Lars for a rebuild

Wamplet

Hehe. Yeah, I've seen a few carburetor posts about Lars and Quadrajets.

I'd rather just buy a brand new one, though.

page62

No you don't. I bought an Edelbrock 1903 to replace my original (don't ask why) and used it for a while. Then I sent my original carb to Lars for a rebuild. Guess which one I'm using now?

But if you insist, the Edelbrock 1903 (with hot air choke) will work just fine. Don't worry about the electric choke, especially in Texas. To save a few bucks, you can buy a remanufactured (like new) version of the 1903, go for the Edelbrock 9973.

cardo0

The best deal on this planet for carbs is a lars rebuild for $100 plus shipping. He tests and tunes them on a real car before sending them back.
BTW you would need an adaptor plate to run an Edelbrock Performer carb (square bore) on a stock Q-jet (spreadbore carb) manifold - or change the manifold. An adaptor will reduce performance, increase carb hieght, reduce air cleaner clearance, and complicate installation. Need to change your fuel line too.
If all this is new technology for you then my recommendation is to stay with the stock replacements. And if lars is unavailible Edelbrock does sell Q-jet replacement carbs #1902 with the stock divorced choke like ours - yes I have a '74 sb 350 too. Or #1903 with an electric choke like your mechanic recommends. But get ready, $450 for the Edelbrocks. Now out here in California there is a great shop called the CARB SHOP (www.customcarbs.com) and they will rebuild, test and tune your carb or provide one for $350 without core charge (telephone quote from Randy).
Go with proven parts and keep your vette a fun hobby.
cardo0

comp

i vote good rebuild

PRNDL

now that you have determined you have a Qjet, look for a number on the side of the carb - if it is 7044206 (if you have an automatic) or 7044207 (4spd) then it is likely the original carb for your car and you should hold onto it. The edelbrock Qjets are direct replacement carbs but they are a bit expensive. You would also probably want to re-jet even a brand new edelbrock Qjet. I bought a #1901 and have been very happy with it. One detail - If you use the divorced choke rather than electric, the Edelbrock divorced choke kit they sell does not fit on the stock manifold. It is designed to fit the Edelbrock manifold.

Wamplet

Thank you for the wonderful replies!

I don't plan on selling my car, so I don't really mind whether a lot of the parts are stock or not. However, I do plan on saving all of my parts, just in case. I was looking at the Holley carburetors over the weekend and there seems to be a much bigger selection among them over Edelbrock. I was wondering if anyone had any suggestions or recommendations on the Holley brand as well?

Thank you for the tip on the spread/square bore.

I'd like to buy a new carbutretor now and then once I get it, I'd like to send my old Q-Jet to Lars for a rebuild.

I have a Jegs catalog and I kinda wanted to get a few more things, like an Air Cleaner by K&N maybe, and then if I got that, I may need to get some new valve covers. (I believe I would have to get valve covers without the breather hole that goes to the air cleaner.) Just curious, if anyone has ordered stuff from them before. Would I be able to ask them questions like in here to them and expect them to be able to answer them? I'd much rather rely on you guys, because you have the car and a lot of you have done the work yourselves on these parts.

As far as the price goes, I don't mind spending the money right now, so money isn't that big of a deal. :o

I had a million more questions, after reading a few catalogs on carburetors over the weekend, but I am pretty worn out right now.

Thanks again for the replies. I really appreciate the suggestions and help.

EDIT:

PRND21, I will check when I get home. I have an automatic transmission, by the way.


[Modified by Wamplet, 3:14 PM 6/21/2004]

page62

Stay away from Holleys -- they need a LOT of care & feeding (see Paul67's thread on this subject). The Edelbrock cars are much more user-friendly. Perhaps you should consider replacing your intake manifold with a square bore Performer EPS unit and sticking an Edelbrock 1406 on top of that. It would look much better than the ugly orange GM intake...and the whole thing would cost less than a replacement QJet!

wugak

I'm doing this exact swap now on my 77. Look at my last post....
PS You can get better prices but I like my speed shop cuz the guys are so helpful. I never buy mail order unless I have to.

I got a 600 cfm Edelbrock performer carb. ($280)
Then I need the Edel manifold since it won't fit stock. ($130)
Then gaskets of course (like $20)
No carb studs in the box so an extra $14
Turns out my rotor and cap are shot... ($28)
New hoses, fittings, sealer etc (about $25)
Air cleaner won't fit now so I bought a nice Edelborck one ($68, but you can get one for way less)
Fuel filter and fittings since the quadra has it built in and edel doesn't ($20)
Thermostat, just because you have it open ($5-8 I think)
Tools: Gasket scraper, timing light, vac gauge etc ($90)

Bonding with the car for a few days and saying you did it yourself..... priceless. It will all be worth it if/when it runs great when I am done.

I'm pretty much a novice and this is something you can do for sure. Just be patient, talk to friends and make a buddy at a local speed shop. The guys here will talk you down from any problem you find.

Good luck!
Tony

Wamplet

^ Excellent idea, page62! My only concern would be the clearance with the hood, since I have seen many posts regarding that, especially with me wanting to put on a new shiny air cleaner. Would I be ok putting in that Performer manifold? I've noticed in the catalog that some manifolds are a bit taller than the stock ones. Would I need to order anything in addition to the manifold and carburetor, like gaskets, or will those be supplied with each piece?

On the 2 valve covers, I believe I need to get the short ones. Would I be correct on assuming that? I will measure the current stock ones that I have and see if i can find a measurement in the catalog, but I have only seen the description of "tall" and "short." I'm guessing the tall covers would be more for the big block engines or engines that have been modified.


I also have a question on the measurements for the air cleaner and how to go about measuring. I'm not too sure what I should be measuring other than the radius of the current one. I believe I am supposed to measure the height from the carburetor, but I'm not really sure exactly where I would measure it from. I'm thinking from the carburetor base, perhaps. Of course that may change if i get the new carburetor as well, but I think Edelbrock probably has one that i can match up with the 1406. Would I be better off sticking with an Edelbrock air cleaner or should I go with a K&N air cleaner?


EDIT: I just saw your post, Tony. Looks like I may want to order the gaskets and carburetor studs. I don't see them mentioned in the catalog with each respective part. :o


[Modified by Wamplet, 4:15 PM 6/21/2004]

page62

The basic Performer or Performer EPS manifolds should fit fine. Use a "drop base" air cleaner so you'll have plenty of clearance. You should use short valve covers for your application.

Do you have a speed shop in your area? It's great fun to visit and check out the goodies...just make sure they're a "traditional" speed shop and not a "tuner" shop. If so, go check it out!

With regards to K&N air filters....save the money unless you want it for looks. I personally witnessed a dyno test where the stock filter, the K&N filter, and NO filter made absolutely no difference!!!

Wamplet

We probably have a speed shop or two around here. Although, I have a feeling it caters more towards Honda Civics and Toyota Celicas. Not even sure if you would call a shop like that a speed shop.

Thanks for the tip on the "drop base." I noticed several air cleaners include that in the description. Regarding the air cleaner, I'm not looking to magically get 500HP out of the car :o, but i would like it to look kinda decent inside the engine compartment.

I'd love to work on the car myself, but by the time I get home, there is no light and I don't have a well-lit garage to work in, so it will be another year or 2, until I am in the right circumstances to do much work on it. I can do some very basic stuff, like change oil, but I'm just not really comfortable to work on it by myself yet. :o Funny story: The day i brought it home, I ran to autozone to get a new air filter and oil filter. Well, it was about 8 or 9pm and I was unscrewing the little wingnut off the air cleaner cover and managed to lose the darned thing. Spent 1 hour looking for it in pitch black dark. Car was parked over a ton of pebbles, so it was really hard to look for it. The wingnut managed to fall down the engine compartment and bounced into the side scoop on the left driver side. :o That's how clumbsy I am.


[Modified by Wamplet, 5:28 PM 6/21/2004]

SanDiegoPaul

I don't know the answer to your specific Q's, but I can tell ya that I have been running the Edlebrock QJet on mine since it was reborn as a stroker. Rated at 795CFM and it's a direct bolt on with no changes for smog devices. Mine runs great...but it's a hot air choke one (#1903) so it's a different application than yours.

I do have a Corvette OEM elect choke quadrajet for sale, came off a wrecked Vette but I don't know the year. I'll sell for a hundred bux if you want.

Wamplet

Ok, I have a question on the air cleaner this time.

I'm spent a good portion of the past day or 2 reading the archives on various manifolds and air cleaners. I can hardly think or see stright right now. :o

I was thinking of getting a K&N filter with the drop-base, since I am currently looking at getting a new manifold and carburetor. ( still up in the air on that one, but I am leaning towards that Weiand Action Plus Manifold or Edelbrock Performer RPM and Edelbrock 1406 carb. The Weiand seems to allow me to have the option of using spread and square bore carburetors. Plus I think it's a dual plane manifold and I am more interested in lower-end performance, while the Performer RPM doesn't. I looked at the Performer (idle-5500 version) and i'd rather get that one over the RPM, but I don't know if the 1406 would work on it. :o

Anyways, pardon my silliness, but my question is if I get an open air cleaner, what happens to the breather hose that went from the valve cover to the stock air cleaner? Do I need to get a valve cover without a hole in it for the old heater hose? I am under the impression that the answer would be yes, but I'm honestly not sure. :o

Tiredol74

You were correct to begin with - the hose runnin between air cleaner base and grommet on the rocker cover is as you say a breather hose or vent tube as you prefer. I'm not sure what you mean when referring to heater hose and valve covers? Jus install inexpensive push-in breather(without side tube) into grommet and remove hose if goin to open air cleaner. Breather has oil soaked filter to allow filtered air into crankcase - good thing. Many older GM's had the vent tube routed to side tube of PCV breather mounted on rocker cover. Hope this helps.