How to:

 

Adapt a Ford NP205 Transfer Case to a Chevy TH350 Automatic Transmission Using Mostly Factory Parts


 

While building my new buggy project, Thanatos, it became necessary to use a driver-side drop t-case to match the offset of my new Unimog 404 front axle.  However, since my SBC was still very healthy and my TH350 trans with manual valve body had recently been built, I had no desire to go to a Ford engine or trans.  This meant that a custom adapter would be needed  to mate the Ford-style NP205 t-case to the Chevy-style transmission.

Advance Adapters DOES make this adapter ... supposedly.  The people I spoke to on the phone claimed that part number 50-6904 would do what I was wanting to do.  However, since what I was doing was not specifically listed as an application in their description, they were not 100% certain that it would work properly.  Since I am unwilling to  drop $600+ on something that may or may not work, I started researching and fitting parts together to see what I could come up with on my own.  As it turned out, I had many of the necessary parts already from my previous TH350 - Atlas II adapter!

Before the pics and data come, you may be interested to know  why I chose the Ford NP205 t-case when I had a perfectly good Atlas II.  Well, Patooyee II's axle ratio after the portals was about 5.25.  The Unimog 404 final axle ratio is about 7.56, so I definitely did not need the extra low-range that an Atlass II has over an NP205.  The Atlas II was also offset to the wrong side.  While I could have bought a driver-side drop Atlas II, the NP205 is stronger and can be modified to be twin-sticked just like an Atlas II can.  (See the following articles on how to Atlas-ize an NP205, they worked like a charm for me and took me about 1 hour:  Link 1, Link 2)  Furthermore, a Ford NP205 is quite possibly the best of all the NP205 transfer cases.  It has a large 31-spline input shaft, huge gears, a strong cast-iron case, and the same 32-spline output shaft in both the front and rear that a Chevy NP205 only has in the rear.  Basically, it has the best of all worlds right from the factory, no modifications needed to be the ultimate in strength.

Anyway, on to the pics and specs.  Hope you enjoy.  --->>>