I have inherited a 2002 RAM 2500, (long story) engine was locked up. Got the engine replaced V10 with V10, also out of a 2002. Now that it's running, the transmission shifts hard, or sometimes it doesn't shift. After talking with my oldest, also the one who helped me swap out the engine, he says he couldn't find where one vacume line went, so he plugged it.

Could this be the problem?

Does anyone have a diagram of the vacume system for this?

Any other possible things to check?

Thanks in advance.