Automatic to manual conversion

I went the other way with an NV3550 to a 42RLE on my 04 and both the T-case and driveshafts were good to go. I don't know if that applies to all years and transmission combos though.

It does not. We need to know what trans he has and which one he is swapping in.
 
Can I convert my tj automatic to a manual and use my current drive shafts and transfer case?
It's possible though we need to know more about your Jeep like its model year. Is there something wrong with the automatic or is a manual just more fun for you? I went the other way, swapping my previous TJ from its original 5-speed to an automatic. My 5-speed was fun on the street but it absolutely sucked on the trails with big rocks I was starting to enjoy.