Transmission swap question

[2tone4by]

I have a 78 Chevy 4x4 with a three speed on the column and a NP205 transfer case. I am wanting to put a th350 in it and have some questions.  Will a th350 transmission from a np203 work on the np205? Also, are the crossover mounts the same and will the driveshafts be the same? Any help much appreciated....

[Dan75k20]

Yes it wil lwork i swapped the np203 out for a 205 in my 75 and it had a 203. the width of the adapter is different you can take a die grinder and make a 203 crossmember work with the 205 adapter or if you can get a crossmember from the 205.

[Irish_Alley]

it depends on the output spline count. the th350 is 27 spline so the only 205 that will work will be a 27 spline. th400 is 32 sm465 depends on the year 10 or 32. 700r4 is 27.  im not sure what the spline count will be on the "three on the tree" trans i dont even know what trans that is

[2tone4by]

You are right Irish, the input on the 205 is 10 splines and the output on the th350 is 27. Advance makes a coupler with 10 splines on one end and 27 on the other, although a bit pricey should take care of that issue. I still would like some thoughts for the driveshaft and crossmember fits cause there were very few 205/th350 setups. My set up is really rare....it is a 3speed Tremec transmission made in Mexico....only one I have ever seen