Falconvan

Hi, I'm new to the forum and looking for some advice on my truck. I have a low mileage 2006 Silverado with 4.3 and a 5 speed manual trans. It's been a great truck and I don't want to get rid of it but I'm having arthritis problems with my left knee and driving a stick on the way home from work in rush hour is killing me. I'd rather just swap the trans to a 4l60e and keep the truck. Changing the trans and steering column is not a big deal but does anyone know what wiring changes Ill need and if I'll need a PCM from an auto truck? Any help would be greatly appreciated.