69 Vacuum hose routing??
 

I am working on my son's 69 Firebird. I need to know where the vacuum advance hooks up, and where the modulator for the transmission hooks up. I also have two vacuum lines that are capped in the back of the carb where the brake booster hooks up. Any idea what those are for?? Pictures would also be nice if possible. Thanks. Aaron

As a general rule, trans modulators need a manifold vacuum source that has vacuum all the time. The distributor advance needs a ported source, where it only sees vacuum when the throttle blades are open above the idle speed.
Pics of your setup and type of carb would help answer your questions.

It has the stock intake and q-jet on it. I will post pictures later.

Here are the pictures of the carb. The vacuum modulator hose for the trans is on the lower left in the first picture. What is the carb fitting on the back for?? Thanks. Aaron

Not sure if you have THM400 or 350. Modulator valve vacuum tube for the THM400 should run to the vacuum port on the front of the carb on the passenger side that you have plugged. The distributer vacuum line is run to the small vacuum port on the lower front driver's side port. Looks like you are running the brake booster hose to the correct vacuum fitting on the back of the carb.

Tom