Going from Quadrajet to Edelbrock 600cfm

[Edhard_Stark]

Hey guys,

I'm looking to swap carbs. The QJ that came with the truck is beat and it doesn't work right, the previous owner hacked it up. It has a manual choke conversion which doesn't work right, the electric choke was gutted and removed. Also my secondaries don't work right, they don't open up. The truck also smells like it runs rich and has some grey smoke coming out the tailpipe, plus the carb looks like it's leaking. I have a great condition Edelbrock 600cfm electric choke that I got for free, so I'd like to put that on there. Besides the adapter for the carb to bolt to the manifold, what else would I need? Do I need conversion brackets for the kickdown and throttle linkage? Thanks

-Ed

 

[bucket]

You will need a couple little trinkets to make it work. But if yow are creative and have a lot of miscellaneous hardware sitting around, you can make it work fine without going to the parts store.

 

[Edhard_Stark]

Since I'm new to carbs, I'd rather write the check then turn the wrench in terms of getting the right stuff to make it work, unless you have pics or a how to on it.

 

[Thunder]

It's a pretty straight forward swap. Seems the last time I did that swap the only thing I had to modify was the throttle cable mount. Just used a file and a hacksaw. The best way to learn something new is to study it and do it.

 

[bucket]

It may depend on the year too. IIRC, when I swapped out the original carb on my '84, I reused the original bracket and needed the stud for the kickdown and needed a bushing to run the throttle cable in the "correct" hole. Or maybe I only needed them because I wanted to leave the original parts with the original carb... it's been a while so it's hard to say. But I remember doing the swap before I went to work one morning.

 

[Edhard_Stark]

Hmmm I'll take a crack at it tomorrow. I guess it shouldn't be that hard. Thanks guys. Btw in terms of the electric choke, how would I go about fixing that up? I don't see the wiring for it, the mouth breathing owner before me must have gutted it while he was making it a hack mud truck.

 

[bucket]

It just gets IGN power from the fuse box.

 

[Edhard_Stark]

Thanks

 

[Swims350]

biggest things, you need a quadrajet to squarebore adapter plate. Not sure on the part number but they say to use ONLY the four hole kind and NOT the wide open middle one.

You need the throttle stud, and the kickdown stud for your trans cable hook up.

pretty sure they are 8009 and 8018.

if you have egr it won't work, mine hit and would not sit down far enough, so I had to buy an egr block off plate. Or edelbrock makes an adapter for it now.

you need an adapter or maybe use the quadrajet one thats on the back for the power brakes vacuum, I can't remember if they have one that comes out or not. If not it's a 1/4 npt on back of the carb and 5/8 on the hard line side.

If you have steel hard line for the fuel it gets cut and adapted, or use rubber line and clamps.

I used stock throttle cable brackets and return spring on mine, but never used it with a 700r4, well once but it never adjusted right before the carb swap.

 

[GreaseDog]

A quality remanufactured QJet will not only run better, but it will not require any modification to install, and once it's set that's it, no need to mess with it ever again.

 

[MadOgre]

I second GreaseDog.

I actually bought an 1806 and instead im gonna redo the throttle shaft bushings in a good straight Quadrajet I got kicking around with the electric choke.

 

[Swims350]

I've never had to readjust any edelbrock. Not to mention how much is a good quad gonna cost?

 

[bucket]

The OP's good carb was free. A quality reconditioned Quad is one of the best ways to go, but I can agree with saving a bunch of bucks.

 

[MadOgre]

If you were to buy a brandnew edelebrock or a refurbished quad you will pay about the same.

the trick is to get educated about the qauds as they really are not any more difficult to go through then an edelbrock.

but it took me a few years to figure them out.

Once you do though, a good candidate for a DIY refurbish can be had for $30 at the wreckers $50 for rebuild kit and another $60 for the throttle shaft bushing kit if it needs it.

 

[rich weyand]

If you are going to get a new Qjet, buy it from Sean Murphy at SMI Carburetors. He will have the air bleeds and all adjusted for your engine setup. Then it's just bolt on and go with no adjustment.

If you go with the Edelbrock, give more info on your setup (headers yes/no, stock 350 or vortec or?) and I can tell you what rods and jets and springs to try to hit the mixture pretty close.

The Qjet is the better carb for street use, I think , because it has smaller primaries, which means the primaries are running closer to their design stack velocity in day to day driving, but ANY properly tuned carb will work better than any other carb that is not in proper adjustment.