TH400 & NP205 Mating requirements?

[Gregsmx]

I currently have a TH350 and NP205 Xfer case set up.

I am wanting to install a TH400, here are my questions....

TH400 questions:
1. What TH400 output shaft length should I be looking for when searching for a tranny in the salvage yards?

2. Is the output shaft length measured from where the output shaft is exposed to the eye, or from the outer face of the TH400 case housing?

3. If I find a tranny with the wrong length shaft, can it be replaced with the correct length output shaft? anticipated cost?

NP205 questions:
4. the adapter between the TH400 and NP205 will have to be replaced (6bolt vs. 4 bolt on the tranny side). Where can I locate this adapter, and are there multiple thickness or part no's. that I have to worry about getting correct, or is just finding one going to be good enough?

5. I need to replaace the input shaft. Where can I find this item?

If I've left out any information that may need to be answered to successfully convert this application, please feel free to provide input, and thanks in advance for all who can help me with this.