Need answers on a swap asap.

[bradford]

Im dropping a new engine in my truck right now and and found I needed to replace the clutch, throw out bearing and crap in my 465. Thats gonna run me a little over 100 bucks.
My truck is an 83 and has a np208 transfer case.

Well, my buddy has a th350 thats connected to a np203 from a 1980 that he will sell me.
I would like to have an automatic.
My question is, what do I need to do to put this th350 in my truck with the np208? Is it longer? will it bolt up the same?
I would put a floor shifter in it so Im not worried about trans linkage, just bolting the tranny to the tranfer case.

My other option is to use his NP203. But then I know I would have to cut my floor for the shifter and then have to get new carpet again.
But would the drive shafts be the same?

We are doing this tomorrow so I need to make an educated decision real fast.

Thanks guys.