Another thing that can cause that exact problem is a faulty throttle position sensor. I had that issue on a Durango/5.9. The sensor is easy to change and not crazy expensive.

On the distributor drive bushing... I believe MOPAR tried to replace the tried and true bronze piece with aluminum. It did not work and there was a service bulletin and I believe free replacement with bronze. I would be surprised if there are many aluminum bushings left on the road.