Swapping np205 in a 78 k5 blazer

[Oryon Hernandez]

I have an np203 in my 78 blazer, I want to swap an np205 in. I have done some research I understand I will need longer driveshaf and a shorter one. The np205 I’m looking at online Fb has the th350 adapter.
Anything else I could need. Different crossmember or transfer case mounts?
Anything I didn’t mention ? Np205 came of a 72 pickup with a th350

More detailed description. I have a 1978 k5 blazer with a th350 and np203, guy that used to own it was a Buick tech and has done some modifications to the truck like r134a ac, and part time 4x4, I talked to him but he kind of rambled so I’m not sure if he installed a cheap part time system in the transfer case or the chain has been stretched pretty bad, there is locking hubs up front not sure what diff. I do have a bad ass clunk sounds like my transmission shattered when I toss it in any gear. So I sent my th350 to get rebuilt before I got educated that it was a worn transfer case.
I would like to do a twin stick system with the 205 but I would hope for there to be a oe style look for the inside of my cab were the sticks will be. I do wonder now if that transfer case select stick will fit in the same spot the old one did if my dash light switch will fit in the same spot.
I don’t know how to add photos off my camera roll but I have pictures of the transfer case.

 

[sweetk30]

The 72 np205 will have the small 10 spline yoke style front cv head or just a yoke . Your 203 will have a flat flange cv style and better .

You can swap the 10 spline for a 30 later gm front output easy .

Transfer crossmember and bushings the same as 78 203 . Might need to move crossmember and possible drill new holes .

Twin stick mod removed the 4x4 light stock . You would have to make your own switch .