replacing a quadrajet with a used holley 600

[dhughins]

my current throttle rod is too small for the big hole and too big for small hole. what parts do i need? what all can you tell me about this linkage? what is different in ford and chevy?

is this the kickdown switch for a th400?my old carb has nothing on it and my searches turn up nothing like this


this is a picture of the intake that is on is it just a stock intake?

[bigmac73]

second pic is just a vac fitting , are you sure you have a TH400, i dont think they have a vac modulator??? kickdown for a TH400 are electronic switched either on the foot pedal or carb linkage

third pic is a stock spread bore manifold and it will not work with a holley unless you buy the adapter/spacer plate

for the first pic, you will just have to rig something up may over size one of the smaller holes with a drill bit or a dremel tool

[GASoline71]

There are kits made by Holley that can adapt almost any linkage to your Holley carb.

That Holley you have is a model 1850 square bore. To use it on the stock spread bore intake manifold, you will need an adapter. Which you have to be careful, as many adapter has caused wicked vacuum leaks.

You will also need a carb stud kit. The stock bolts for the Q-jet won't work as well.

Gary

[dhughins]

Here is a before pic.

[dhughins]

I have the adapter kit

My problem is my throttle rod is just a rod with bends at both ends with holes for cotter pins. I was looking at speedway website and see throttle rods and ends that appear to screw on. You reckon I can get the correct size and use that?

What about also removing and blocking off egr?

[dhughins]

How was my quadrajet kicking down?

[GASoline71]

The linkage kit from Holley will have a bushing that will fit in the large hole, that should accept your older style linkage arm.

http://www.holley.com/types/Throttle...ce%20Parts.asp

Also... if that is a used Holley... make sure the floats are set correctly , and see what jets are in it before you go much further. Some cats will get all wonky with Holleys thinking they have to constantly tune them. Which you don't. So who knows where the floats are set, and what jets are in it.

It already looks like the accelerator pump has been "adjusted" too much.

Are you gonna rebuild it before you install it?

What rig is this engine in?

Gary

[ZombiePopper]

Stupid question;
Why not rebuild and run the quadrejet?
Good carbs IMO.

[Grumpy old man]

want to sell your old junk quadra jet ?

[GASoline71]

Rebuilding a q-jet has its piftalls. They are great carbs for their era. 99.9% of them need a throttle shaft rebush as they are all over 25 years old. Not to mention the plugs need to be epoxied in the base plate. So depending on the OP's mechanical prowess... a Holley is much easier to rebuild if you ask me.

Having rebuilt pretty much all of the major 4 bbl carbs... The Edelpuke/AFB (Always Friggin Backfiring) are the easiest, followed by Holley, and then the Q-jet and Thermoquad.

Gary

[zeldman]

Never heard of an edelpuke. What is it and who makes it? Never seen a good holley either, used or new.

Second picture is a vacuum fitting. Looks like the line going down the rear of the motor is for the vacuum modulator for a TH350 transmission.

Third picture is just a stock 4 barrel intake. Nothing special, actually good for marine usage, like an anchor.

The engine looks like it came out of a mid 70s to possibly very early 80s pickup or car. In stock form they were not known for power.

Like GASoline71 states, the major problem with Q-jets is the throttle shaft. It wears out where it goes through the main body causing a nasty and intermitant vacuum leak. There is a bushing kit made to fix that problem. Lot of used holleys have the same problem.

[GASoline71]

Originally Posted by zeldman

...the major problem with Q-jets is the throttle shaft. It wears out where it goes through the main body causing a nasty and intermitant vacuum leak. There is a bushing kit made to fix that problem. Lot of used holleys have the same problem.

That is very true as well.

Used carbs are a crapshoot no matter what brand or style.

Gary

[bigmac73]

you can block of that EGR valve, but if you are going to do that , i would just get a new intake manifold, that is a square bore, with out the egr setup and also remove all that other old emission crap as well and that will clean up your engine compartment as well,
you can find a good used intake on craigslist for cheap

[bigmac73]

Originally Posted by dhughins

Here is a before pic.

after looking at the pics again , i would defiantly find a good used intake and pull those valve covers as well and clean and paint those up as well make the top end brighten up a bit

i have owned a few edlebrock carbs in my day and i always had a stumble or hesitation in them and yes i tried changing springs and metering rods ect ect as the techs suggested always switched over to a Holley in the end

[dhughins]

I've been looking for a used performer intake but appearantly they don't sell on craigslist in this part of the country. I'm on a small budget and was just wanting to replace the quadrajet right now. It has multiple problems. It stumbles off idle, it does return all the way to idle when you let off you have to pull on the pedal,choke doesn't work.

I will want to sell the quad once I get the holley running. I have instructions from holley website as far as setup goes.

Right now I have got to get the throttle rod problem solved. I read a cool article about getting heim joints and threaded rod and making my own, but I don't I find all that at my local hardware places. We'll see.

[TxTan]

PowerNation: Detroit Muscle on Spike TV is currently showing how to do a Quadra Jet rebuild!


Update:

Well...they just kicked the Q-jet to the side, and rebuilding an Edelbrock Carb.

[landy]

You may want to consider rebuilding the Q-jet. You can ship it out to a quality carb rebuilder and they'll do it all. By the time you finish swapping all the parts to make the Holley work, you might be ahead rebuilding the Q-jet.

FWIW, I've got a Q-jet on a '72 Blazer that was rebuilt before I got it, and it works well. I've also got a Holley on a '71 GMC that the P.O. installed, and am having some problems with it.

[ZombiePopper]

Originally Posted by GASoline71

Rebuilding a q-jet has its piftalls. They are great carbs for their era. 99.9% of them need a throttle shaft rebush as they are all over 25 years old. Not to mention the plugs need to be epoxied in the base plate. So depending on the OP's mechanical prowess... a Holley is much easier to rebuild if you ask me.

Having rebuilt pretty much all of the major 4 bbl carbs... The Edelpuke/AFB (Always Friggin Backfiring) are the easiest, followed by Holley, and then the Q-jet and Thermoquad.

Gary

Gary, that's pretty much EVERY carb regardless of brand that's been run 25yrs not just Q-Jets.
I've run/rebuilt em all as well, I find Holleys easier to rebuild/tune personally but that's because they're what I use/used the most.
But I agree, I've used the EdelCrock carbs MANY times, and I'm not a fan, but oddly enough I like the actual Carter carbs lol.

[dhughins]

I'm gonna try and build this throttle rod.of course no local parts place or hardware stores here have these Heim joints. So I'll wait for them to be delivered. I know this is from a f**d website. http://www.fordmuscle.com/archives/2...rottleLinkage/

[geezer#99]

Why make one when you can buy one?
Look here!
You can look on summit too for the carb adaptor you'll need.
http://www.summitracing.com/int/sear...ttle%20Linkage

[Stickman]

Buy Cliff Rugles Q-jet rebuild kit and his book on rebuilding them and go for it. Another option is there is probably some members on here who rebuild the Q-jets and if not go over to the V8Buick forum, there's a half dozen guys over there who do it.

[imjeff]

+1 on rebuilding the Quadrajet. I would also move that water temperature sender off the thermostat housing as it's reading outgoing water temp plus probably reducing flow capacity.

[ZombiePopper]

Originally Posted by dhughins

I'm gonna try and build this throttle rod.of course no local parts place or hardware stores here have these Heim joints. So I'll wait for them to be delivered. I know this is from a f**d website. http://www.fordmuscle.com/archives/2...rottleLinkage/

Depending on what length you need, here's a nice hemi joint double adjustable shift rod (from a sport bike believe it or not) nice solid, attractive rods, I got it cheap from a guy parting out his R1, so look around, ( if you can use it let me know)

[dhughins]

I need 1 about 12.5 inches long. Thx though.

[bigmac73]

if i remember right i had a piece of threaded rod on a 69C-10 years ago, and it just had two adjustable ends on it for the carb linakge and the rod coming up by the firewall