Carburetor options?

[Steve Beecher]

I have a 68/C10 PU w/350 and a Rochester Quadrajet 4 barrel carb..The primary throttle shaft is worn and i believe this is causing the truck to idle rough and basically run like sh!t, when it warms up it's better but no always. The power brakes don't work very well ether and i suspect maybe low manifold vacuum may have something to do with this carb?..I've given it the "carb spray" around the base of the carb while running and the idle smooths out but when i removed the carb i couldn't find any major probelms with the thick paper base gasket, maybe it's sucking enough air thru the worn throttle shaft..Also i've heard some Quadrajets require a metal plate under the carb between the thick paper gasket and the manifold?..

Should i get this Quadrajet rebuilt and the throttle shaft re-bushed or replace it with a Holley, or??

Any recommendations appreciated..........Thanks!

[mikeoj]

Rebuild!

[jimfulco]

Get your Q-jet rebuilt. Don't just exchange it, get that specific carb rebuilt & rebushed. It's already calibrated for your engine. Write down the 7-digit number from the driver's side on the outer front of the secondary barrel, & make sure that's the one you get back.

If there's an open passage in the intake between the front carb bolt holes, you need the metal plate. That passage is for exhaust gases, & is often choked with carbon. My '72 came from the factory with the plate, but no passage, and also a thick gasket with plastic doughnuts at the bolt holes. Be sure your new gasket has these doughnuts, because they keep you from overtightening & warping the throttle body. Fel-Pro sells the plates & the good gaskets.

[trukman1]

I "THIRD" that! Get the Rochester rebuilt and make sure it's the same carb!!! Go Rochester! Bye!

[67chevemall]

Rebuild it yourself! It is great fun!I'm just learning!
It is cheaper and good times! No old part a55gump will steal parts from ya!

Finding a big steel container for the gunk was the hardest part so far!

[Dean]

Sounds like I'm the minority here, but I would take it off and put it on your shelf. Then buy a new Eldebrock for it. I have a shelf full of quadrajunks in my garage. Only two more to replace on the Elcamino SS and 85 C20.... lol

[72C203503ONTHETREE]

Go to autozone or similar place and get a carb for a 70 Camaro, its set up for a nice 350 and will have the throttle shafts redone and be cleaned up. Thats what I did to get by until I get the top end redone with race parts. Its $123 with your old carb as a core. Just tell them its for a 70 camaro 350 four barrel and thats all. Edelbrocks are fine as are the Carter carbs that the edelbrocks are a copy of but they tend to puke fuel out the vents when sitting on a hot engine thats not running. You will need to get a heat sheild under the carb or at least a plastic or wood spacer. I had an Edelbrock and a Carter that did the same thing, the heat sheild/spacers fixed that problem. A freind had a 55 chevy that would flood out at idle if it sat long enough with an Edelbrock, so he had to get the sheild also. I went to a Barry Grant Speed Demon for the El Camino, much better carb than the Edelbrock and better than the regualr Holleys. The Quadrajet is a good carb for everyday driving and even racing if you can set it up right. I like mine so far but will be replaced with a Carter AFB soon when I get the heads, intake, and cam installed.

[Steve Beecher]

Thanks for the tip guy's. I decided to re-bush/re-build. The C10 i have is sweet (dad's bought it new), it'll pass anything but a gas station ;-)...9<10mpg....yiks. My vw runs 12's in the 1/4 and gets better milage, but i must admit, not near as reliable :-)

[TsgtE662]

I just rebuilt the QJet on my truck last weekend. Now it runs great! Its a bit touchy on the gas pedal now so I gotta get used to how it accelerates now. Without tryin it wants to spin the tires.

The kit cost me about $20, and a new choke pull off another 7.
I decided to rebuild it rather than replace it when I saw the serial numbers are 7040202. It is a 70 and has a 402, which I thought was kind of cool. A new carb at Parts America is $205 or so.
This was my first carb to rebuild. Not very hard at all. I used two cans of carb cleaner to clean everything.

I am happy with it so far.

[jimfulco]

Years ago, I bought a brand new, not rebuilt, Quadrajet from the local Rochester dealer. It was allegedly a direct replacement for my '72 Nova carb. This was before anybody locally was set up to rebush the throttle shaft bores. The new carb didn't work worth a damn. Flat spots here, hard starting there, etc. I got my original carb redone locally a few years later, & it works just like it did when it was new. Somebody stole the "new" one a few years ago, & although I was a bit pi$$ed that he stole it, I don't consider it a big loss. The same local rebuilder here quoted me $135 to $165 to rebuild somebody else's Q-jet last week, depending on how many new parts it needed.

[crazy longhorn]

Spreadbore carbs are really hard to beat for mileage. With that said, I am a big Holley fan & have run several spreadbore Holleys. A 4175 (vac secondary) will work nice on a mild sb.....the only drawback, is that they arent cheap(in the $350-400 range for a 650 cfm carb). If you can get your carb rebushed, & rebuild you may be best off. Good luck,crazyL