joepackersrock

I need to find a place to run the HVAC controls off of so can I get vacuum from either of the 2 outlets on the front of my carb? One is a ported vacuum outlet and the other is for the PCV valve and is pretty huge. Although its unrelated to carbs, if I can't use any of the above sources could I put a two way splitter in the vacuum hose that goes from the intake manifold to the brake booster? Or would that cause me to go screaming into a tree...

joepackersrock

I believe I may have found the answers to my own questions, but I'll post what I figured out just to make this a worthwhile post in case anybody else has a similar issue.

The ported vacuum output won't work very well for something that needs a vacuum supply at idle because it sees no vacuum at idle. I'm not sure about the PCV output but it doesn't seem like a good idea to me. I found a picture of another car that had a tee screwed directly into the intake manifold that split the vacuum two-ways, between the brake booster and the check valve that supplies vacuum to the HVAC controls and the vacuum resevoir ball thats under the drivers side fender. Heres the parts I found on Summit, first is the tee that screws in and second is the straight pieces that screw into the tee that allow you to hook a vacuum hose to it. Stainless steel ones are kinda pricey though.

http://www.summitracing.com/parts/PRS-1042/

http://www.summitracing.com/parts/PRS-1044/

DoubleV

Go to the boneyard and get the vacuum port piece from the rear of the intake on any Olds 307. They have 2 'outlets' on them and would just replace the single outlet of the one in your pic. I assume the threading is the same.

Alternately, run a cheap plastic vacuum T and you should be fine.

camaronewbie

You'll also need a vacuum canister for the HVAC controls. Your 3rd gen came with one, it's a plastic 'orb', it's located under the driver side headlight - you have to get at it from under the car, taking the plastic cover off. You want to T off the intake vacuum source, with a line that runs to the 'orb' with a check valve, and another line that runs to the HVAC controls. That way, when there's low vacuum, the HVAC controls still operate using the vacuum 'stored' in the orb.