OBD1 to OBD2 plus upgrade?

So I successfully put a obd1 5.9 magnum into my 69 Dart 4spd and have been driving it all spring and summer and love it, but now I want more. I originally went OBD1 because that was the donor I had,wasn't confident I could even make it run and read it was easier. I bought a complete 98 ram 1500 with a 5.9 as a donor. I know the pcm and plug ins are different, but l think all the wiring and sensors are the same other than a 2nd o2 sensor. Is it just a matter of depinning my wiring and putting on the 3 plugs for the pcm? Also while I am changing the computer I want to change the cam using the Hughes upgrade cam kit and I am going to do the kegger mod. Are these mods going to require a reflash of the pcm? This will be my first time doing any upgrades with a computer controlled system so just looking for some guidance. Thanks