ill_driver

I am getting to the final stages of my engine swap, and I am totally and completely confused. All the brackets that fit onto my quadrajet do not come anywhere near close to fitting on my Holley. The bracket (for the throttle cable I think) that went on the back of the quadrajet has no where to fit on the back of the holley. The line that comes from the reservoir behind the master cylinder that plugged into the back of the quadrajet has no where to plug in. The bracket (the line comes all the way from the trannh) that is supposed to go on the intake is way too short (I put an inch spacer in). PLEEAAASSSSEEE HELP! I am sooo close, yet so so far....
Thanks,
Karl


[Modified by ill_driver, 5:36 PM 10/16/2003]

The Dude

First of all, put the throttle cable bracket for the Q-Jet in the workbench and forget about it. You are going to need an aftermarket throttle cable bracket. There are many to choose from. Browse Jeg's, Summit, etc.

As for the brake booster, you're right. You're going to need to pull engine vacuum from somewhere else. If your Holley is laid out anything like mine your ohnly choice, really, is to attach the brake booster to the large fitting on the front of the carb. But then you have no PCV. Bad news. You could use a "T" fitting so that PCV and the brake booster both draw vacuum from this source. Or you could drill and tap your manifold's plenum under the rear of the carb and install a fitting for the brake booster. Either scenario will work.

I don't quite understand the issue with the trans vacuum line. That usually connects to a fitting in the manifold. Could you use a longer piece of vacuum line to make the connection, or am I missing something?

[EDIT]OH, you must be talking about the trans kickdown cable connection to the throttle lever, maybe? There's a lot of adjustment in that cable so you're probably OK even with the spacer. You'll have to hunt up a longer cable or lose the spacer if not.


[Modified by The Dude, 9:48 AM 10/16/2003]

ill_driver

It is not the trans vac line. I want to say the speedo cable, but I think I am wrong. It is a cable that has a spring on it and the cable goes about 10 inches past the sprig and has a 3 inch slotted end where you can slip it over a ***...

The Dude

:lol:
You're fast. I was editing my comments to include remarks about the kickdown cable as you were replying.

ill_driver

I am ready to get it running :cheers: ;)

ill_driver

On my Holley 750 DP, there is a hole in the front just opposite where the fuel line goes in. I assume that is what you are referring to for the brake booster? There is no threading in that hole though....
Karl

The Dude

If we're talking about the same vacuum fitting at the front of the carb, you're right--it's just a barb end with no threads. Just slip the hose on it and slip the other end on the barb at the brake booster. Put in a "T" fitting at a convenient location and plumb your PCV there.

You know how to adjust the kickdown cable? Look at it where it slips through the square hole in the bracket. Just aft of that, if you look closely, you'll see a couple of slots that look like you can put a screwdriver in them. This is a little "gate" that, I believe, contains the ratchet mechanism. Pry it up, but not out. Now, attach the cable to the throttle shaft. Leaving the "gate" up, crank the throttle to wide open. Extra cable will come out. Hold the throttle wide open than slide the "gate" back down into place. You're done.

Tom454

On the power brake vacuum line... the idea is to have it secured to manifold vacuum on a port such that a failure of another device on that same port will not significantly affect braking assist. This usually means the brake vac line gets its own threaded-in nipple (so it can't fall out), and in many cases a steel line instead of hose.

I have seen several applications where the nipple is shared with a much smaller vac line, but never with a large or same-diameter line. This is not to say it hasn't been done by GM. I can't say for sure because I have not worked on every vehicle that has ever been produced.

You'll have to use some "judgement" here.

If your manifold has an available large diameter vac port, then you should consider using that instead of a carb port.

My 86 Silverado with a factory Q-Jet is set up that way from the factory.
Your manifold may have a port with a pipe plug in it that can be used??

Worth a look-see.

The Dude

Yup, you're right. Most manifolds have a threaded fitting at the rear someplace that's used to get vacuum down to an automatic transmission. He could use that for the brake booster if he has a manual.

I don't think I'd use that one for PCV though--I believe you need something directly into or above the plenum for that so the blowby gases are distributed evenly throughout the mixture instead of getting sucked preimarily into just one or two cylinders.

He could also drill his carb spacer at the rear and tap that for an NPT fitting that would accomodate 1/2" or whatever vacuum line and use that for the booster while keeping the barb at the front clear for PCV.

Lots of things he could do.


[Modified by The Dude, 12:51 PM 10/16/2003]

ill_driver

I ended up splitting the vaccum line on the back of the carb for the PCV and the Brake booster. I got a bracket from O'Reilly's that bolted on the carburetor for both the Throttle cable and kickdown. So i think I got it all figured out. Thanks for all your help!
Thanks,
Karl :cheers:

The Dude

Man, I'm glad you picked up on my earlier mistake. (I just did reading your last post). Of course the large, barbed vacuum fitting on Holleys for the PCV is at the rear of the carb and not the front as I said. Sorry if I caused any confusion. My memory is crap since I went to a lot of parties in the 1970s--if you catch my drift. Next time I'll look before I post. :yesnod:


[Modified by The Dude, 9:34 PM 10/16/2003]

ill_driver

Ain't no tang The Dude... Lets go bowling :cheers:
-Karl Hungus


[Modified by ill_driver, 5:51 AM 10/17/2003]