86 K10 350 w/ stock Rochester Quad. Jet -Rebuild carb or go with bolt on replacement?

[WDE86]

Question in the title. I've got an '86 K10 pickup with the original Rochester Quadrajet carb. I'm almost certain it's time to get it rebuilt/replaced. Just wondering if I'd be better off having it rebuilt or just buying a brand new carb compatible with the truck's current stock setup.

Also, if I decided to go new. What are some of my options? I'm carburetor dumb but I do know that there are some that would require a manifold swap as well and I'd like to avoid that.

[cjlloyd81]

If you stick with a Q-jet (spread bore) you won't have to worry about manifold swaps. Even if you go with a square bore (edelbrock/holly) you can get an adapter plate.

If you were closer i'd invite over and rebuild it for you and teach/show u. Quadrajets are an odd carb because people either hate them, or LOVE them (me). They're a great carb once you get them all dialed in. And no I'm not a holly/edelbrock/carter/etc... hater. I love all carbs but have mostly played with Qjets. I have 5 sitting in my shed right now that I pick up for next to nothing and rebuild.

If you end up getting a new one and don't have to core return ur old one let me know

-Chris

[tkeduk8r]

stick with the quadrajet for sure....they are not that bad to do and will be the best for mileage and power... PLUS your way ahead because you dont have to modify anything!!! Ive done close to 100 of these carbs and it is something YOU can do... I have gotten high school kids to do them too, so you should be ok... Cliff Ruggles has a great book out there with color illustrations and great descriptions on how they go back together... dont have an ISBN on hand but do a quik search on Amazon and youll find it..... hope that helps...
--Mike

[WDE86]

Originally Posted by tkeduk8r

stick with the quadrajet for sure....they are not that bad to do and will be the best for mileage and power... PLUS your way ahead because you dont have to modify anything!!! Ive done close to 100 of these carbs and it is something YOU can do... I have gotten high school kids to do them too, so you should be ok... Cliff Ruggles has a great book out there with color illustrations and great descriptions on how they go back together... dont have an ISBN on hand but do a quik search on Amazon and youll find it..... hope that helps...
--Mike

But don't I need a few specialty tools to make adjustments and whatnot once I get inside it? I was under the impression that this was the case.

[Old Truck Man]

I never had much success with rebuilding Q jets.I usually buy a adapter and adapt to a 2bbl or a square base carter(edelbrock) I once told a customer who asked how to fix a Q jet? You take a BFH and set it on the sidewalk and beat it till its as flat as you can get it. Then you install something good!

[geezer#99]

Originally Posted by WDE86

But don't I need a few specialty tools to make adjustments and whatnot once I get inside it? I was under the impression that this was the case.

Common tools needed:
Big flat screwdriver.
Small flat screwdriver.
Needle nose pliers.

[BADAZ chevy guy]

When I had my last truck, 73 3/4 ton, it had a Q-Jet on it but the carb was in real bad shape and the shaft seals leaked. So, I bought a new Edelbroc 650 and tried that first. Great performance... lousy gas mileage. Then I bought a reman Q-Jet. Better mileage, but I lost a bit of the performance. The Q-Jet just wasn't as responsive off the line. Other than that... I've always loved Q-Jets and have rebuilt several over the years.
My new truck, 1977 C10, I'll be going to Edelbroc because I want better responce and I'll be running Vortec heads and aluminum manifold.

[crashz]

I like the Q-jets for power an mileage. But they take a bit of tinkering to get just right. i guess all carbs do, but I could never get my holleys set up to run as smooth and clean as the Q-jets. Had both on 350's and 454's, and both times I was able to get much more from the Q-jets.

[imjeff]

Definitely Quadrajet. Back before the internet people used to give them away if they got a "bad one". It was usually an ignition problem! The ones that got some people hating them had internal vacuum leaks (easy fix). A lot of people don't like them because someone told them not to. Holley did a lot of very good advertising, Rochester, not so much, but I still prefer the Quadrajet. No constant blowing of power valves, no fuel leaking gaskets, a bazillion different metering rods, small (responsive) primaries.......what's not to love?

[Irishbleueyes]

You can get decent performance and mileage out of an Edelbrock. Advantages are theres no gaskets below the float bowl to leak, the primaries do have metering rods and different tension springs to lift them at specific vacuum pressure like the Qjet but not on the secondaries. Metering rods can be changed in seconds, they're right under the air cleaner. Edelbrock has many jet sizes and metering rod sizes. Also affordable. Install an AFR (air fuel ratio) gauge and really dial it in it. Its like doing your own dyno work, you'll love it

[Old Truck Man]

Originally Posted by Irishbleueyes

You can get decent performance and mileage out of an Edelbrock. Advantages are theres no gaskets below the float bowl to leak, the primaries do have metering rods and different tension springs to lift them at specific vacuum pressure like the Qjet but not on the secondaries. Metering rods can be changed in seconds, they're right under the air cleaner. Edelbrock has many jet sizes and metering rod sizes. Also affordable. Install an AFR (air fuel ratio) gauge and really dial it in it. Its like doing your own dyno work, you'll love it

Everything you state is spot on. I grew up messing around with the Carter AFB carbs. Its what im familiar with and I like mechanical secondaries. The edelbrock is nothing but a rebaged carter.

[Irishbleueyes]

Originally Posted by Old Truck Man

Everything you state is spot on. I grew up messing around with the Carter AFB carbs. Its what im familiar with and I like mechanical secondaries. The edelbrock is nothing but a rebaged carter.

Yes, just an ol carter. The quadrajet does have the better secondary setup but edelbrock does have the AVS carb that has some kind of adjustable secondary that I haven't fooled with yet. Edlebrock doesn't have a wide enough variety in metering rod sizes down in the small end. Small ci motors need the smaller jets and smaller metering rods and they are really sensitive from lean-even-rich just by a thousandths or two to make a dynamic change on the AFR at least I found out. Had to make rods just for mine by sanding down the power end with emery cloth and a drill...

[bnoon]

Rebuilt and properly adjusted, any carb sized appropriately to your engine will perform well, no matter the brand. For my basically stock 86, a rebuilt Quadrajet was the choice. Started with the flick of the key and one pump every time, even through winter... For my 454, a 750 Holley will most likely ride along, and the built 350 in my 74 will be a Holley 600.

[motornut]

my 78 has a square holley on it,and i've tried to fix it,rebuild it? no
79 has a 2B,both going to stock 4B Q-jets
picked this used intake up for that change over
you can see the second set of holes

[rich weyand]

I took the metering jets down a size to put the A/FR in the middle of the range of metering rods where there are more choices.

[naphtali5725]

QJet's were only installed on millions of cars, so they must be a bad carb right? LOL

great carb, no need in anything else... get a good carb rebuild kit for it...

go to Cliff Ruggles web site, and get a rebuild kit

or get in contact with Lars Grismund he'll rebuilt it for a fair price, quick turn around that's who did mine... excellent

[tucsonjwt]

On my 3 squares, I have had 2 new Carters, 1 new Edelbrock, 2 rebuilt Q-jets from auto parts stores, and got my current Q-jet rebuilt. Of all these, the current rebuilt Q-jet was the best, but the local rebuilder did not do a very good job. I will go with one of the better online Q-jet rebuilders next time.

The Carters and Edelbrocks worked OK, but I had trouble with the quality of the parts. The throttle shaft would jam on one Carter. On the Edelbrock, the throttle valve was too big for the opening (or the opening was improperly machined) and would jam.

[Irishbleueyes]

Originally Posted by naphtali5725

QJet's were only installed on millions of cars, so they must be a bad carb right? LOL

great carb, no need in anything else... get a good carb rebuild kit for it...

go to Cliff Ruggles web site, and get a rebuild kit

or get in contact with Lars Grismund he'll rebuilt it for a fair price, quick turn around that's who did mine... excellent

I don't think anybody is saying anything bad a about a Qjet and I think we all agree its the best carb made. For sure we all agree if you could buy a brand new one, we all would. Maybe some day fuel injection will be affordable for all...

[naphtali5725]

Originally Posted by Irishbleueyes

I don't think anybody is saying anything bad a about a Qjet and I think we all agree its the best carb made. For sure we all agree if you could buy a brand new one, we all would. Maybe some day fuel injection will be affordable for all...

yeah, 2000 bucks or so for EFI is ridiculous, glad there are a few QJet specialists still around

[motornut]

Originally Posted by naphtali5725

yeah, 2000 bucks or so for EFI is ridiculous

sure is ,i picked up a new Quad for my 79

[Irishbleueyes]

Originally Posted by rich weyand

I took the metering jets down a size to put the A/FR in the middle of the range of metering rods where there are more choices.

What size Edelbrock carb do you have and what size jets came in it and what size jets did you end up with?

[rich weyand]

Edelbrock 1406. Stock jets and rods are:
Primary jets: .098
Primary rods: .075+.047
Secondary jets: .095

I am running A/FR of 14-14.5 (cruise), 13.5 (power), and 12.5 (secondaries) on a 350 with stock low-compression heads, dual plane manifold and headers with these jets and rods:
Primary jets: .095
Primary rods: .064+.055 (polished down from .067+.055)
Secondary jets: .095

I also run the 8" step-up springs stretched an extra 1/4" in length for earlier transition, because my cam (Comp 12-300-4) draws like 18" of vacuum. In the winter I switch to .062+.052 primary rods to keep the same A/FRs with the colder, dryer air.

Performance is great, transitions are crisp and without stumble. Dyno simulation predicts 275hp at 4000 rpm and 422lbft at 2500 rpm at the flywheel. In recent mileage testing in best tune I get 9.5 mpg on short trips around town (5-10 miles one way with lots of stop and go), and 11.5 mpg at 65mph on the highway.

[Irishbleueyes]

I have the 1404 500cfm, came with 86 primaries 95 secondaries 65x52 rods. Im down to 80 primaries and I also made my own rods, 61x57 and my afr is 14.7-15.1 cruise 13.5 power. Made the front end so lean had to go to 104 secondary jets. Thinking of trying the 77 jets to get 14.7 power. My 283 comes alive at that afr. It did give me considerably better gas mileage and stopped the raw fuel smell coming out of the exhaust pipe plus my oil is staying clean...

[midnight rambler]

Research edelbrock 1902. Cant get them new but can find them rebuildable or just rebuild ur stocker

[gchemist]

Checkout these guys for stock carbs: http://www.nationalcarburetors.com/