I did what you are planning. Except mine was at 100k and need less attention. However my previous 7.3 needed some work.
7.3 fueling is something to look at;
Fuel bowl mods
fuel rail crossover mod
At your milage Injectors, HPOP also.
Passenger rail hard line can start leaking, it gets rub...
I thought on this for a long time before choosing True Tracs F/R. They worked pretty good until I got into 2ft of snow on Mormon Emigrant Trail.
I need more time practicing left foot braking sure, but a front Eaton Elocker is nagging at me. It would still do what I need on snowy roads and maybe...
$1300 which is normal for rebuilds around here, they agreed to the core swap so there's no "hostage".
Factor in the shaft, tail-housing, and warranty and it's a no brainer unless you build transmissions.
I believe swapping the shaft requires rebuilding it.
I just had a shop rebuild me a 4x4 4r100 and the took the 2x4 4r100 as a core, that's the easiest way. (keep your sensors and make sure the hardline on the side matches)