stalling with AC on, coming off of idle

Here's a way to test for any vacuum leaks from those hoses.
Clamp shut the hoses coming off the manifold fitting or plug the hoses and use rubber caps on the fittings.
Then drive the car with AC on. Air will came out of the wrong dash outlets but that won't matter.
See if it still stalls.
This would test for any leaks associated with those hoses and components.
In today's repair shops a smoke machine would be used.