Quad to Edelbrock carb swap, what do I need?

[WillSquared]

Hey fellas, the truck died on me this week. Turns out the pickup coil was bad in the distributor and must have been going bad ever since I bought the truck in March as it runs like a completely different animal now. Went ahead and put new plugs and coil on it while we were at it.

Anyway, decided to go ahead and bite the bullet since I already have the intake manifold (Edelbrock EPS 2701) and ordered up the 600cfm Edelbrock 1406 carb for it. My future father in law is who does most the work on it as he is very knowledgeable on these trucks and he prefers the Edelbrock stuff. I just wondered what I would need to complete the install on my 86 C10 350? Any linkages or just misc things for the swap? I personally am not very mechanically minded so I wanted to ask and make sure I had all we would need before hand.

 

[Skweegle89]

I believe all you will need is a spread bore to square bore adapter. If you don't have an adjustable throttle cable bracket you might need one of those as well. I wish you hadn't already ordered the eddy so I could talk you out of it.


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[WillSquared]

Thanks for the info. Yeah, I know there are a lot on here that prefer the Quads and like I said I dont know enough to have an opinion on it. I just know what he prefers and so I try to go along with that whenever possible.

 

[Swims350]

pretty sure it should but up to the eps without any adapter plates, so basically you need some 3/8 rubber fuel line, clamps, a filet I'd recomend you get and use. Then you need the throttle stud and if you have a th350 or 700r4 the kickdown stud, pretty sure they are 8009 and 8018 or something like that, summit has em, jegs, local chain parts stores carry them too.

of course if the carb is new it should have the base gaskets, but you need intake gaskets, I don't think they come with it but maybe, look in the box for th eintake and see.

air cleaner, the drop base style may not work, I couldn't get ours too I went with a 14x3 raised base, some have used certain drop bases ones but all I tried would not work, stock ones might. I'm pretty sure my stock 88 fit it fine but never tried the stock 84 or 86 base, aftermarket drop bases I had would not. or you may just get a spacer, the spacer or raised base may require you to get a longer stud for the air cleaner.

if you have 700r4 I recomend you get the tv cable bracket or geometry correction bracket to make sure it fits and works right or your trans will die.

anything else I 'm unsure it's been awhile. maybe a little piece of another size hose or a fitting for power brakes, or maybe reuse the quadrajet one. I think we reused our fitting from the q-jet.

if you can reuse the stock throttle bracket(if it bolts to the intake and intake has the holes for it) then it should be fine and so should the return spring.

choke, is it electric choke? was the q-jet?

manual chok eis easy if you have one use it if not buy a universal kit.

chrome universal throttle and kickdown brackets are cheap and work good.

 

[WillSquared]

pretty sure it should but up to the eps without any adapter plates, so basically you need some 3/8 rubber fuel line, clamps, a filet I'd recomend you get and use. Then you need the throttle stud and if you have a th350 or 700r4 the kickdown stud, pretty sure they are 8009 and 8018 or something like that, summit has em, jegs, local chain parts stores carry them too.

of course if the carb is new it should have the base gaskets, but you need intake gaskets, I don't think they come with it but maybe, look in the box for th eintake and see.

air cleaner, the drop base style may not work, I couldn't get ours too I went with a 14x3 raised base, some have used certain drop bases ones but all I tried would not work, stock ones might. I'm pretty sure my stock 88 fit it fine but never tried the stock 84 or 86 base, aftermarket drop bases I had would not. or you may just get a spacer, the spacer or raised base may require you to get a longer stud for the air cleaner.

if you have 700r4 I recomend you get the tv cable bracket or geometry correction bracket to make sure it fits and works right or your trans will die.

anything else I 'm unsure it's been awhile. maybe a little piece of another size hose or a fitting for power brakes, or maybe reuse the quadrajet one. I think we reused our fitting from the q-jet.

if you can reuse the stock throttle bracket(if it bolts to the intake and intake has the holes for it) then it should be fine and so should the return spring.

choke, is it electric choke? was the q-jet?

manual chok eis easy if you have one use it if not buy a universal kit.

chrome universal throttle and kickdown brackets are cheap and work good.

The carb and intake are new. I got the Edelbrock gaskets to go along with it (which dont come with front or rears?) and then the bolt kit from Edelbrock for the manifold as well. I do have an aftermarket pro form air cleaner. Ill cross that bridge when we get there I suppose. Ive got a TH350 so no worries on a tv cable bracket. It is an electric choke, as was the quad. Thanks for the info. I'll look over at edelbrocks website for those studs.

 

[Skweegle89]

Yea if the Intake is new also you won't need the adapter, so forget that.


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[Swims350]

if it doesn't have the ends seals use thick layer or silicone/rtv or buy a set and use them.

 

[WillSquared]

I figured that was the intended way of sealing the ends but thought I'd throw that out there. No worries there. I found the studs and will get them ordered. Hopefully it'll go as smoothly as possible.

Related question, the connector to the carb choke is broken. I have it zip tied in place right now but it's not terribly secure. Can I buy a new connector anywhere? I assume the edelbrock electric choke uses the same style connector.


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[rich weyand]

The choke connectors on the 1406 are just 1/4" male spade connectors. Get some 1/4" female spade crimp connectors and crimp them on the existing wires. Sometimes these are called "disconnects". Get insulated ones, or put heat shrink over them, so if the hot wire pulls off it doesn't short to the manifold.

You will need a spacer ring on the top of the carb to use the stock air cleaner, as it will not clear the fuel entry on the 1406. I strongly recommend against replacing the stock thermostatic air cleaner with any non-thermostatic type, because the engine will run like crap when the weather's cold. Carb heat keeps the carb from icing up and aids carburetion, giving better mileage and performance.

The spacer I used is 3/4", which is plenty. I bonded it to the bottom of the stock air cleaner with 3M Weatherstrip Adhesive (get it at any auto parts store), and then put the air cleaner on the carb with the ring to hold it in alignment until the adhesive set up. Here's the spacer I used:
http://www.jegs.com/i/JEGS+Performance+Products/555/50071/10002/-1

If you do the spacer, you will need an air cleaner hold down threaded rod that is 3/4" longer. It's just 1/4-20 threaded rod. Get it at the hardware store.

You also need to get the Edelbrock airhorn gaskets, because you have to take the airhorn off the carb and set the float height to spec. Yes, I know it's new; they are always wrong new right out of the box. The gasket is Edelbrock 1499. They come five in a package.

Know that the Edelbrock will be rich for the stock 350 in the power circuit and lean in the cruise circuit. They have to sell them rich in the power circuit, because they're used on many different kinds of engines and most people won't tune them, and if you run hard lean all the time you can burn up the top end of the engine. It's set up lean in the cruise circuit for mileage, but they overdid it. So you will want to tune it. Easiest is to do that when you have the carb open because then you can change the jets as well as the rods.

Stock 1406 setup is: .098 primary jets with .075/.047 rods and .095 secondary jets.

Best 1406 setup is: .092 primary jets (#1425) with .062/.052 rods (#1441) and .095 secondary jets (no change). You can also try .065/,052 (#1460) rods for better mileage, but they may need to be changed out during the winter.

OK 1406 setup, requiring no jets change, is: .098 primary jets (no change) with .070/.057 rods (#1418) and .095 secondaries (no change).

These setups are all for Edelbrock 1406 on a 350 with dual plane manifold on low-compression 76cc heads. Cam doesn't seem to make much difference to this setup over a wide range, from torquer through stock to winder-upper.

You will also want to get the step-up spring assortment (#1464) and put the 8"Hg springs in so the power circuit on the carb comes in sooner. This will prevent lean sag in transition.

Sounds like a lot, but all these parts are like $10 apiece. so gaskets, jets, rods, and springs will come to about $50.

 

[Swims350]

it's already been covered he has an aftermarket cleaner.

I never had one single issues running non thermostatic crap air cleaners inw inter. Ours does not run bad, never had any driveability issues at all.

I've never changed jets and rods either, ran em stock out of the box on 350's mild 350's with cams and stock 305's never any issues, just set the idle mixture correctly and done.

good info from somebody who has changed and played with jets and such though. I've never changed any and never had a problem, it may be rich or lean but my plugs are always clean like they should be and never any smoke, overheating, or any real symptoms of anything.

 

[MrMarty51]

Send Me that Q~Jet. Well, it was worth a try.

 

[WillSquared]

Thanks to everybody for all the great info. Cant wait to get it switched over.

 

[MadOgre]

it's already been covered he has an aftermarket cleaner.

I never had one single issues running non thermostatic crap air cleaners inw inter. Ours does not run bad, never had any driveability issues at all.

I've never changed jets and rods either, ran em stock out of the box on 350's mild 350's with cams and stock 305's never any issues, just set the idle mixture correctly and done.

good info from somebody who has changed and played with jets and such though. I've never changed any and never had a problem, it may be rich or lean but my plugs are always clean like they should be and never any smoke, overheating, or any real symptoms of anything.

OK yes I think the air cleaner is just a personal preference thing, However if you run in frigdid temps with out a winter front then Rich is 100% correct.

The jetting depends on elevation so unless willsqaured and rich are at the same elevation there most likely will be a difference in what is used for tuning rods and jets.

Yes the Edelbrocks are extremely rich right out of the box unless you are at sea level.

The throttle geometry correction bracket is a must if running a 700r4 it is not optional!

The Edelbrock universal throttle/TV cable bracket is a piece of **** so don't even bother looking at it.

You will need Felpro 1256 intake gaskets and don't EVER install rubber end seals on the intake manifold. It will leak form day 1 if you do and probably will just fall out. Always use RTV gasket sealer to seal the ends of the intake manifold to the block.

I strongly recommend you run a fuel pressure regulator at no more than 6 psi.

The carb should come with the insulated choke electrical connector. It should also come with a base gasket. You will have to buy the carb to manifold stud and nut kit.

It is a good idea to buy a heat insulator gasket though 1/4"

You will need the GM style throttle stud.

You will also have to plug one of the water jacket ports.

For a throttle bracket try and find an old manual style GM bracket and then use a grinder to make it fit. works awesome!

If you have a 700r4 then use Edelbrock #8036 for the TV cable. If you don't you could use it for the throttle then. It says it does both but it does not. There is only one usable position on it so its either throttle or TV but not both. I used an old GM throttle bracket, modified it and then used #8036 for the TV cable. Otherwise you will have to fabricate your own bracket.

 

[Swims350]

that's funny we have very cold weather here no issues, ever the things never run rich because plugs are always normal color not wet and not black. we've also ran those universal brackets you say are so much junk, for years and years never had any problems, work just as they should.

we also always use rubber end seals and I've not had any leak. I'm actually afraid to just trust a glob of silicone across the front and back.

I guess to each their own.

and yes you definately want a heat insulator with an alum. intake I forgot about it and how much trouble I had in the summer heat without it.

sea level heights definately come into play on carb adjustments, and we're above sea level here for sure.

 

[MadOgre]

I don't know dude! Rubber end seals seriously? It is more crucial to have a heat gasket on a stock cast iron intake vs an aluminum intake cause the aluminum does a better job of dissipating the heat.

You obviously don't have a 2701 with a TV cable using that universal bracket. Cause they are complete ****! The freakin bracket bends like 1/2" every time you do WOT, perfect candidate for broken 700r4. On top of that you can not get the correct cable geometry for the TV cable because they are 2 short!

I guess black oil is normal to you too? cause that's what rich jetting does. spark plugs will only show up if you are way off the scale. Phone Edelbrock and ask them your self. They will tell you that even at sea level they are slightly on the rich side!

If you use the correct felpro 1256 intake gaskets you shouldn't have too much of a problem with heat soak as the intake really doesn't get all that hot. The insulator gasket is just for insurance that you don't.


Everything is application specific! So guys can not tell you that it worked on mine so it will work on yours. Just doesn't work like that! Everything depends on what you have and how you have it set up.

Rubber end seals on a stock cast iron intake= OK on an aluminum after market = NO FREAKIN WAY!