Edelbrock 1403 or 1406 ?

[Already Gone]

Is anyone using an Edelbrock 1403 or 1406 Carb on their stock, mine has H Pipe duals from ram horns back, 1972 350/350. I'm thinking of changing from the stock Q-Jet and it would be nice to have real world opinions on how good/bad they are. I had a 1406, which was great , on my last truck which I had for 13 years and it was on top of a 396 and its 600CFM so I wonder if the 1403 at 500CFM woud be a better choice for a stock small block.

[toolboxchev]

I lost a bit of performance when I put on my edelbrock 1406 but I added the manual choke with cold start issues. It is a breeze to tune.

A smaller carb make no sense to me unless someone knows the cfm of a stock quadrajet. I am told some of them could be capable of 700 or more cfm.

[leftybass209]

I'm running a 1406. The honest truth, not worth it at all, and the only reason I stuck with it was because it came with the truck. After getting the carb, it's possible you'll have carb boil and need a phenolic spacer or that you'll have too much fuel pressure as the Edelbrocks don't like much over 5.5psi.

If your Quad is in good condition, you should stick with it or have it rebuilt and tuned appropriately.

If you really want an aftermarket carb, maybe look into a 500-600 cfm Holley, or one of the Street Demon carbs.

There's nothing at all wrong with the Edelbrock and it can be tuned to be a strong runner or a gas sipper. I just can't rationalize the cash outlay on the carb and associated parts when you won't see much, if any, benefit. There's a lot of complaints about the Edelbrock too. However, it's usually poor tuning, too much pressure, or it gets too hot causing vapor lock, as I mentioned previously.

[custom10nut]

Agreed. If you still have the Q-jet, get it rebuilt and tuned. If you go with the Edelbrock, the 1406 is the way to go. The 1403 is too small.
When I bought my truck it had a Carter on it, and it ran well until I put the truck in storage for five years. I tried to clean it out but went the "buy a new carb" route.
They are real easy to tune and tweak, with the numerous jet/spring/metering rod kits available. I went the extra step of putting a power plate under the accelerator jets (pm me for info, as I don't advertise for products), and could not be more pleased.

[AJC]

I just went from a Edelbrock 1406 back to a Quadrajet. It was a fine carb but has its issues like mention above. A Quadrajet is a 750cfm or 800cfm depending on year.

[6T7 C10]

Already Gone, I agree with your thinking. You can definitely make either the 500 or the 600 cfm work well but in my opinion the Edelbrock 1403/1801 500 cfm would be the better one. The smaller carb is tuned slightly more for performance and would be good till 5000+ rpm on a stock 350 and offer great vacuum, velocity, throttle response and economy.

[AJC]

My fuel economy was awful with my 1406. I up 2 mpg with a swap to a Quadrajet and still working on tuning it. If economy is what your looking for a spread bore will almost always out do a square bore. Swapping to an Edelbrock you will need a square bore intake or adapter. A fuel regulator for 5.5 psi ( stock fuel pump is 9 psi).

[Already Gone]

Originally Posted by AJC

I just went from a Edelbrock 1406 back to a Quadrajet. It was a fine carb but has its issues like mention above. A Quadrajet is a 750cfm or 800cfm depending on year.

A Q-jet on a small block is 750CFM that is lots for a stock small block. Thanks for the input and opinion guys/gals. I think after reading this i will get my Q-Jet rebuilt as the truck runs great with it but the truck has 88,000 miles and I doubt if its ever had a rebuild. Pic is of my Q-Jet.

[BROWN 70]

hi already gone, as been stated the early q-jets are 750 cfm. don't let that scare you, you can limit the secondary travel or don't floor it al the way. I,ve been building q-jets for many years and if you make sure the primary shaft isn't loose ( vacuum leak ) and the well plugs aren't leaking, (epoxy or better yet remove them and tap and plug them,) q-jets work really well. cliffs q- jet has anything that you will need. your q-jet in the picture looks like the float might be getting heavy. (fuel stain all over front or carb) and the vacuum port on the passenger side , are you using that to your air cleaner or? remember to by a good kit that is resistant to corn gas. good luck. BROWN 70

[Already Gone]

Originally Posted by BROWN 70

hi already gone, as been stated the early q-jets are 750 cfm. don't let that scare you, you can limit the secondary travel or don't floor it al the way. I,ve been building q-jets for many years and if you make sure the primary shaft isn't loose ( vacuum leak ) and the well plugs aren't leaking, (epoxy or better yet remove them and tap and plug them,) q-jets work really well. cliffs q- jet has anything that you will need. your q-jet in the picture looks like the float might be getting heavy. (fuel stain all over front or carb) and the vacuum port on the passenger side , are you using that to your air cleaner or? remember to by a good kit that is resistant to corn gas. good luck. BROWN 70

Thanks for your post. I figured the fuel stain was telling me something was up and it was getting to be time to adddress the carb one way or another. The reason the vacuum port is like it is is because I changed from the stock air cleaner to a dual snorkel that has no provision for the line that came from that port. Before I changed the air cleaner when I started the truck, even after being parked for 5 1/2 months during the Winter, two pumps on the gaspedal and awy she went right on the auto choke . Now it bucks farts and blows black soot till it warms up and I'm wondering if thats happening because the vacuumn is not hooked up. When I first put the air cleaner on I had ascrew in the hose but removed it thinking maybe it needed to suck air. Is Cliffs Q-Jet a vendor?

[AJC]

Cliff Ruggles owns Cliff high performance. Which is dedicated to the rebuilding and modification's of Quadrajet carburetors. He also wrote a book on it.
Web site http://cliffshighperformance.com/

[BROWN 70]

Hi Guys, I would plug the vacuum port on the passenger side, it is a vacuum leak now. as far as your choke, it looks like its full on in the picture. unless it was really cold that day it needs adjustment. I would buy cliffs book it has a wealth of info in it. if you decide to buy parts from him, he,s really good about answering questions. he also has a fourm to ask questions. hang in there when tuned correctly q-jets work well for both gas milelage and power. BROWN 70

[El Dorado Jim]

I love the edelbrock 1406 carbs, I have them on several of my trucks...I dont know why guys think they are bad....easy to rebuild and have plenty of power, I hate holleys and rochester carbs are harder to rebuild

[woody82]

I have a 1400 on my 402 big block the guy at Summit told me that would work just fine.I personally don't care for it.Thinking it needs a fuel pressure regulator or a spacer under it.

[leftybass209]

Originally Posted by El Dorado Jim

I love the edelbrock 1406 carbs, I have them on several of my trucks...I dont know why guys think they are bad....easy to rebuild and have plenty of power, I hate holleys and rochester carbs are harder to rebuild

They aren't bad, they're just often pigeon-hole'd by people that don't know how to tune. However, they aren't as explicitly bolt and go as Edelbrock suggests. They most of the time require extra parts which aren't included with the carburetor, such as a phenolic spacer, thicker gasket, a new fuel pump or a regulator.

Some people can get by without those things depending on climate, or if their trucks are already so equipped.

At the end of the day, there's been numerous magazines and real-world tests that have proven that either one can outperform the other, in either fuel economy or performance on a given day depending on tuning skill, cfm, and engine build. Realistically, unless aesthetics are a concern the switch winds up costing money (potentially more than just the carb) for a net of nearly 0 gains in performance or fuel mileage. Even giving a solid and probably exaggerated 1 hp throughout the power band, and a solid 1 mpg extra on average to the Edelbrock, it's still not a cost effective way to spend $350-400 bucks new, when other performance gains can net a significant increase in power with no hit to mpg.

Again, it's not a knock against Edelbrock as I have one, its just a non-biased view of the most cost effective solution to the concern presented.

[rockyrivermark]

I just finished up my restoration and finally on the road
I installed a 1406 (600 cfm) to replace my quadrajet.
I matched it up to an edelbrock intake.
Also converted to HEI.
Engine is 350 with TH350 trans
Truck runs fantastic. Electric choke is nice and easy to adjust. I tuned carb with vacuum gauge which was really easy.
I did have to add
a phenolic 1/2" space to resolve heat soak but that's only a $15 part and 15 min to install.
Personally the set up works great for me.
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[MagmaJct]

I'll share my experience. I have the Carter AFB which is basically the 1405 IIRC.

It was on the truck when I got it with an adapter plate. Soon after I installed a phenolic spacer. It always had a cold start problem. I eventually upgraded to the electric choke, but it can be finicky. (Low unstable idle, prone to stalling until about a minute after a cold start.)

I eventually got a Quadrajet to see if I can do better than 10 MPG with a 350, but engine vacuum is 10 - 12, and the Quadrajet can't work with low vacuum unmodified.

[toolboxchev]

Originally Posted by MagmaJct

I'll share my experience. I have the Carter AFB which is basically the 1405 IIRC.

It was on the truck when I got it with an adapter plate. Soon after I installed a phenolic spacer. It always had a cold start problem. I eventually upgraded to the electric choke, but it can be finicky. (Low unstable idle, prone to stalling until about a minute after a cold start.)

I eventually got a Quadrajet to see if I can do better than 10 MPG with a 350, but engine vacuum is 10 - 12, and the Quadrajet can't work with low vacuum unmodified.

Well that is where I decided to fix some of the running problems with my truck. I had extremely bad cold start issues being that the bottom end is in need of a rebuild yet I still use it everyday.

So I put a manual choke 1406 on mine. Its been over 7-8 years and other than simple tuning with a quality vac gauge its simplicity and problem free use I really like.

Now that I know more can be done with them I will look into that in the future. I saved my old Quadrajet and its a numbers matching carb, still works. If I build a power motor in the near future I will be leaning toward that as it had more cfm capability.