Help with 1973 Pontiac 6.6L

by evilbro03 Sat Sep 30, 2017 6:39 pm

Recently decided to try to restore a 1973 Grand Prix. Since I haven't been under the hood of a car for 40 years need a lot of help with the engine as I can't find anything that really helps me with the vacuum set up. Apparently a previous owner haphazardly played with the ignition system and installed an HEI but didn't rewire for it. This I can do, thinking of going back to a point system. My questions range from the "Yes, I'm stupid" to help me. The intake manifold has a plain single nippled vacuum connection that is not connected to anything and I can't figure out what should go there. Also, no ported vacuum switches. I would like help/advice on how to eliminate the vaccum module in-line with the distributer advance, I think its called a TCS, if there is a replacement or way to redo the whole thing for originality let me know, or if I'm better off getting rid of it. I plan on posting pics of the underhood mess I have and am open to suggestions on what goes where.

by Mcarlo77 Sun Oct 01, 2017 1:00 pm

First off, welcome to the site. There are a few Grand Prix owners on here...just not sure if any of them own '73's to offer up some guidance. One of my favorite salvage yards I visit has at least one '73 sitting there with the engine intact. Perhaps, if you don't find your answers in the coming weeks, I could check it out on my next trip out there and take some pics/make some notes. Meanwhile, I did find this article published in Hot Rod magazine that may or may not shed some light.

http://www.hotrod.com/articles/pon-0509-1973-emissions-control-systems/

by bigredlaguna Sun Oct 01, 2017 2:28 pm

You can buy a brand new harness that is wired properly for an HEI. Might be a good idea any way if the insulation of the wires you have now is getting brittle.

http://www.wiringharness.com/

The Pontiac selections are a bit confusing to read, but these guys are good at communicating with you about what they can do for you.

I bought a couple of harnesses from them and am pleased with the product. I understand they market their stuff elsewhere and it may be possible to get a better price from another source.

Welcome aboard, and I look forward to hearing about your progress.

by bigredlaguna Sun Oct 01, 2017 2:54 pm

Where you live may help determine if you keep originality or not also. I think a 73 is old enough to be exempt from compliance almost anywhere.

If you are not required to have the emissions systems working to tag it, I would get rid of all the unnecessary ports and hook up the vacuum advance directly to a manifold vacuum port.

by fasrnur Sun Oct 01, 2017 6:47 pm

Welcome aboard sir!

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Help with 1973 Pontiac 6.6L

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Re: Help with 1973 Pontiac 6.6L