Quadrajet Vacuum Connections
Thread Starter
Drifting
Joined: May 2002
Posts: 1,546
Likes: 282
From: Back in Nebraska
Quadrajet Vacuum Connections
Getting ready to install my quadrajet on my 350. Does anyone have a vacuum diagram as to what vacuum port goes to what component? I have a diagram for the A/C, wiper, and headlight vacuum systems, but what I don’t have is a proper connection diagram or instructions for the other vacuum systems like the vacuum advance, automatic transmission vacuum, and power assisted brakes. Getting down to the last of the installation process, won’t be long now!
Melting Slicks
Joined: Aug 2003
Posts: 2,135
Likes: 2
From: Dayton Oh
Re: Quadrajet Vacuum Connections (Apocolips)
Thread Starter
Drifting
Joined: May 2002
Posts: 1,546
Likes: 282
From: Back in Nebraska
Re: Quadrajet Vacuum Connections (marshrat99)
Thanks for the replies. I have a Carter QJ # 7040202 off of a 1970 350/300. On all of the diagrams it shows a vacuum port to the right, (looking at the front of the carb) of the fuel inlet. Mine does not have such a port. There is one above and to the left of the fuel inlet right above the choke pull off port, and a hole in the carb’s base located just to the right of the PCV port. On the left side of the carb sticking out through the choke pull off metal frame is a long vacuum port. The only other ports/holes in the carb is in the rear top. It is just a hole, but is open and free for air to flow. All of the above is assuming that you are looking at the carb from the front. Is my carburetor just different, or is it typical for that year?
:banghead:
:banghead:
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
Re: Quadrajet Vacuum Connections (Apocolips)
I am not familiar with that carb. Here is a large file showing the connections on a 1979. There may be a few hints there.
http://temp.corvetteforum.net/c3/paul79//engine_003.jpg
http://temp.corvetteforum.net/c3/paul79//engine_003.jpg
Burning Brakes
Joined: May 1999
Posts: 1,132
Likes: 1
From: Bradford,Mass.,USA
Re: Quadrajet Vacuum Connections (paul67)
For 70s, the port coming out of the front of the carb is for the distributor vacuum. The rear port is just a vent for the TCS system.
70s had a unique to 70 TCS system that used both ports. You can just port the vacuum can to the front port and plug the rear port.
70s had a unique to 70 TCS system that used both ports. You can just port the vacuum can to the front port and plug the rear port.
Burning Brakes
Joined: Sep 2000
Posts: 922
Likes: 0
From: Maine
Re: Quadrajet Vacuum Connections (Mag Red Man)
Thread Starter
Drifting
Joined: May 2002
Posts: 1,546
Likes: 282
From: Back in Nebraska
Re: Quadrajet Vacuum Connections (Frank75)
Thanks everyone. With this info I can get to work. Man this forum is the greatest! But don't stop, if anyone else has further info keep it coming.
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