[chrise321]

I installed the above carb on my 69 GTO(AT). My car does not have a stock cam and the person I bought it off of had no idea what cam is in it. Right now I am getting about 10"hg of vacuum at idle and it idles poorly(surges). I believe the power piston spring is too stiff so I ordered an edelbrock spring kit to try a lighter spring. Right now the mixture screws don't appear to have any affect on idle. I was trying to adjust to get a little more vacuum to help out with my power brakes. I put this carb on to replace the old chevy truck Q-jet that was on it when I bought it. It was in need of a rebuild as the throttle shaft had quit a bit of play and I thought I had a vacuum leak. My questions are, what main rods and jets would you recommend. Right now the jets are 69 and the rods are unmarked (probably generic rods from a poor rebuild). Secondary rods are BE with an M hanger. I also seem to have a lack of ports on this carb. I have the full manifold port at the rear that I want for my power brake booster. I have two more on the front of the carb. One that is about midway up on the body(passenger side) that I suspect would be for EGR. I don't plan on using this one. The other one is on the carb base on the drivers side of the fuel inlet. Is this one ported or manifold vacuum? I need to hook up vacuum for my transmission modulator and my vaccum advance. Any ideas on where I can do this. Also, where is a good place to buy various vacuum fittings if I need one to go directly into one of the plugged ports on my intake manifold?
Cliff, if you read this, I live down the road from you in Delaware. and more than likly I will have you build this carb for my application (I know the idle circuit needs adjusted at minimum) in the future. But for now I want to have a little fun this summer in my new ride.
Thanks in advance everyone.

[chrise321]

Does anyone have any suggestions for my vacuum fitting placements?

[Malky]

I have found it is very difficult to get jetting advice as there are so many variables in each q'jet that affect the main jet/rod combo.
Re the bad idle, it may be nozzle drip. If you look down the primary venturi when idling, do you see drips of gas falling off the main discharge nozzles? If so, do a "nozzle drip" search on this forum.
If not, a check on the idle mixture is to close the choke plate over a bit. If this improves the idle, it is too lean. Pull a vacuum line off the carb. If that helps, it is too rich.
To figure out the ported and manifold ports, connect a vacuum gauge to the big port at the back and take a reading at idle. Then connect the gauge to the other ports. If the reading is a lot lower, it is ported. If it is the same, it is manifold.
THe threads in the manifold are likely NPT tapered pipe threads. You can buy adapters with this pipe thread on one side and a hose barb on the other in most automotive stores.

[Cliff R]

The power piston spring is probably not the answer, the lack of vacuum at idle will still not pull sufficient fuel down from the idle system. Since you are so close, give us a call when things warm up and we can arrange bringing the entire vehicle up for custom tuning the carburetor. We're only about 35 miles from Delaware.....Cliff

[67cruiser]

If i may throw my 3 cents worth in here, first off you need at least 72 jets to begin with, that thing is running super lean, what do you plugs look like?? i bet there white as snow!, secondly your probably right, sounds like wrong metering rods for sure, thirdly if its a rwebuilt carb. shoot just pull the top off and see whats going on, check float level for one, what size needle and seat are you running, Cliff is the Ga roooo here for sure, your doing the right thing by taking it to him, he will probably open up the idle tubes for you to. Good luck with your carb.

[chrise321]

Thanks for the info guys. I took the car for a spin around the block last night and it definetly needs work on the idle and off-idle circuits. Runs great when you get into a little bit. Cliff, I will definetly contact you when the weather around here warms up a bit. Hopefully I can get it running well enough that I am confident that it will get me to your place without dying. It has stranded me twice now due to either carburetor or ignition troubles. I have replaced pretty much all of the ignition items so I hope that I can concentrate on the carburetor.
Once again thanks guys.