[frank88chevy]

does th400 come in a 4wh drive case if so what # transfer case bolts up?

[speedydeedy]

To the best of my knowledge the case is the same just the out put shaft is different. Many transfer cases fit, my son has a NP208 on his.

[Crosley]

Originally Posted by frank88chevy

does th400 come in a 4wh drive case if so what # transfer case bolts up?

this applies to a married trans and t-case:

there are 3 different shafts for 4x4 t-case applications.

203 t-case

208 & late 205 t-case

early 205 t-case is a 2WD output shaft

Adapters and t-case must match the out put shaft length.

[F&J]

Here's some info on the 205 heavy duty T-cases:

The 3&4-speed standards & TH 350 are the same T-case casting and input shaft. But each has a different stock GM adapter to bolt it up.

All of those 205's have a male spline on the input shaft.

The 205 T-case is different for the TH-400. That's because the output shaft for the 400 trans fits into a female spline on the input shaft of the "TH-400 only" 205 T-case. They had to make that 205 input shaft bigger which requires a bigger O.D. input bearing & hole on the T-case. The GM adapter is unique to this TH-400/205 setup. It came out in 1980, and maybe only one year?...because they started using 208's?? after that?

[F&J]

Also, I did do a swap back in 1982, making a 2wd 1979 GMC with a TH-400 into a 4x4 with a 205 box.

That 79 GMC 400 2wd trans did not need a different output shaft for the trans. I did order a new output shaft for a 400 (to 205) but after looking at them, there was just a few minor things different like snap-ring grooves & lack of a threaded hole for the 2wd output yoke. (all of which were not needed) So, I sent the new shaft back. That entire driveline is still here & working fine....but now in a 66 Chevy K-20.

I also converted a 4-speed 205 T-case by stripping it bare, then sent it out to machine the input bearing hole bigger to fit the new TH-400/205 input shaft & bearing that I bought from GM. I also had to order the correct adapter from GM. All the other parts inside the 205 were the same. Those parts probably are not available anymore from GM.