need help I'm swapping cabs 6.0
 

please help!! swapped my crushed 04 lariat crew cab to a 03 xlt crew
Both trucks are crew cab the only difference is my lariat had leather power seats and where the xlt has cloth and the xlt was a manual truck and my lariat cab that was crushed was automatic transmission. Do I have to change all the wiring harness behind my lariat dash to have the xlt cab work on my truck? My lariat cab had the selector switch 4x4 where the xlt cabs a 2wd truck originally also. Honestly need help so anyone that can help would be very appreciated!! There will be no lariat things going in the cab so idk if I need to pull the fuse box and wiring harnesses to put in the xlt?
Main thing I'm really asking is if the wires under the hood on the driver side inner fender are the same hookups that go through the firewall between 03-04 or BC its a manual cab going on a auto truck was the harness different for the trans hookups ? And if not can the be changed without changing the whole cab wiring harness? I'm not putting the lariat things back in the truck no power seats or anything but I am changing the PCM BC the one on the manual cab is already gone.