67 Vacuum problems

Message board troubleshooting 101:
Is this a condition that suddenly occured, or has it been around for a while?
Have you recently done any work which may have influenced this condition?
Verify if it is indeed a vacuum leak.
There's a couple of easy ways to do this:
While the engine is idling, use some spray carb cleaner, and spray around the vacuum hoses and lines, including where they connect to items. Take your time and do a very clse visual inspection as well. The engine speed will increase when the carb cleaner gets sucked in.

Get a vacuum gauge and connect it to a vacuum port. See if it's reading a steady number, or when it's fluctuating.

Of course check the obvious such as, dirty air filter, dirty fuel filter, tight and clean battery connections, etc.