After cleaning, you could probably do the swap in an afternoon for possibly Zero dollars.
I would probably only swap the clutches and bands etcetera, unless one has more or better anything.. and would install the better sprag.
If you end up swapping gears, make sure they are the same and swap everything together, keeping the output shaft and the planetaries together as a set.
AFAIK, the VB's should interchange, but save the 440 one, in case you don't like the way the kitted one shifts.
If the Clipper convertor is clean, I would just reuse it.
No disrespect but, before I would install a GVod, if it would fit easy, I would have chosen a Mopar 4-speed od, which puts the od unit, into the trans, and is a .69od compared to the GV at .78.. The .69 is worth about 10%more rpm-drop at 65mph than the .78. Looking at it from the otherside, you could run 10% more rear gear for the same cruize rpm.
IE; 4.56 x .78=3.55s whereas 5.13 x .69=3.54 ..
Those 5.13s would get you a lil more drive off the line and a lil more climbing/passing gear.
On a different note, you can use the GVod to make a short third, by selecting od after Second gear. Then into 3od, you get the same .69 rpm drop, it's just not as low as if would be, in the Mopar od-box.
I have one of those Gv's, with a Manual Trans, and in my case, using it as a splitter, I love it. It takes a lottachit on the upshifts, just never try to downshift into it. and especially make sure it's out of the loop/disengaged, when backing up. They have zero-tolerance for backing up in gear.
But I imagine, since you already have the GV, you must have thought it over pretty carefully.