Yes a vacuum leak will cause what you are describing. Look at all the usual suspects and plug the wiper line just for the test. I had a vacuum wiper motor cause all sorts of evil stuff in the past. Went with electric to get away from it.
1, Carb base
2, Intake manifold: 3 places
3, Intake valve adjustment. Surprise!
4, Exhaust valve adjustment. Surprise #2!
5, Float level, if too low it will lean out and starve under load.
6, Vacuum advance, if it leaks you will have trouble.
This will give you a good start. fix one problem at a time. Keeps the stress level down a bit. Also look at the air filter. If it is blocking the air flow you will have more trouble. Enjoy!
