it seems you've got an extensive knowledge on the subject, what would be necessary to do the opposite? Zf6 to 5r110. Yes I know, very uncommon but for more practical for me.Yes, you can use the rear plate from the manual truck on yours. Don't listen to the people that tell you you're better off getting another truck-you know your truck, you're probably attached to it. Given the 6.0's lack of tolerance to poor maintenance, why gamble that the truck you buy is going to last? The 6.0 conversion is VERY easy. Just get the trans harness/pcm out of a manual trans truck, as well as the floor pan. Other than that, it's all a bolt in ordeal. I've done a few, PM me if you have any questions.
clutch/pressure plate/throwout bearing/pilot bearing/trans mount
rear engine adapter/plate
floor pan (or a big hammer)
pedal assembly (clutch and brake, accelerator is the same)
complete trans harness/manual trans PCM (or a reflash, but it's easier this way)
Keep in mind many aftermarket exhausts don't fit the manual trucks without some massaging.
and the hardest part, the transfer case has a different spline pattern. You can use the auto transfer case, but you have to change the input shaft. Easiest to get a manual trans transfer case. Disregard this if you have a 2wd truck.