Convert TH350 from 2wd to 4wd?

[mw67rs]

I have a rebuilt TH350 for a 2wd and was planning to put it in my 4wd. I noticed the output shaft is longer on the 2wd. I did some searching on Youtube on how to disassemble a TH350. It looks like you need to remove all the guts for the transmission to get the output shaft out. Looks a little intimidating but not impossible. Anyone ever swapped a 2wd output shaft for a 4wd in a TH350.

I am fairly mechanical and have rebuilt engines but never a transmission. Is this something I should try or leave it to the professionals? I thought I could pull the only TH350 that was in the truck apart to get the output shaft out of it and if it looked like something I could put back together then give it a try on the rebuilt one. What do you all think?

Can anyone recommend any good videos or books if I do decide to give this a try?