Author Topic: 1970 455HO QuadraJet 7040268 Vacuum Ports  (Read 2218 times)

Offline thor7726

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1970 455HO QuadraJet 7040268 Vacuum Ports
« on: May 01, 2016, 06:03:34 PM »
Hi all,
I'm getting close to running my rebuilt 1970 455 with the first qudrajet (7040268) I have ever owed or messed with.  What vacuum ports do I need to hook up and where?  I have a 4-speed manual with manual brakes so I'm thinking I only have the vacuum advance for the distributor.  Would that be the vacuum fitting that comes directly out the center back of the QJ?  Should I cap the rest?  Or do I need them somewhere else?
Any and all help is appreciated!
Thanks,
Pete

Offline carmantx

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Re: 1970 455HO QuadraJet 7040268 Vacuum Ports
« Reply #1 on: May 01, 2016, 09:36:21 PM »
You typically use the port on front, driver side to go to distributor.  You do want to block all ports that arent used.  Does your car need vacuum for operations of air vents?  What are you working on?
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Offline thor7726

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Re: 1970 455HO QuadraJet 7040268 Vacuum Ports
« Reply #2 on: May 02, 2016, 06:20:49 PM »
carmantx,
Thanks for the reply!  I'm working on a 1970 Pontiac 455, 4-speed manual, manual brakes, no other options that require vacuum.  I just ordered a cap/plug kit.

Offline qjetsrule

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Re: 1970 455HO QuadraJet 7040268 Vacuum Ports
« Reply #3 on: May 03, 2016, 12:08:14 AM »
if you are keeping it pure stock, you need to aquire a vacuum diagram. there are vacuum lines that operate the air cleaner thermostats. the Muncie also has a ball switch which operates a vcs (vacuum controlled spark) solenoid on the intake. it's not written in stone but qjets with an even number on the end were for automatics and odd numbers were for manuals. good luck