ENGINE idles low and almost dies after revving

Been waiting for someone else to reply, but since no one has, I can share how this is solved on Chrysler products. The Engine Computer loses its memory when you disconnect the battery. It has to relearn "minimum throttle" before it will know when it must be in control of idle speed. As with most other things, Chrysler makes that real easy. To meet the conditions for the relearn to take place, drive at highway speed with the engine warmed up, then coast for at least seven seconds without touching the pedals.

Your truck will also have to go through a relearn. Sorry that I don't know the exact procedure but it usually just involves driving it.