TH400 & NP205 Mating requirements?

[Gregsmx]

I currently have a TH350 and NP205 Xfer case set up.

I am wanting to install a TH400, here are my questions....

TH400 questions:
1. What TH400 output shaft length should I be looking for when searching for a tranny in the salvage yards?

2. Is the output shaft length measured from where the output shaft is exposed to the eye, or from the outer face of the TH400 case housing?

3. If I find a tranny with the wrong length shaft, can it be replaced with the correct length output shaft? anticipated cost?

NP205 questions:
4. the adapter between the TH400 and NP205 will have to be replaced (6bolt vs. 4 bolt on the tranny side). Where can I locate this adapter, and are there multiple thickness or part no's. that I have to worry about getting correct, or is just finding one going to be good enough?

5. I need to replaace the input shaft. Where can I find this item?

If I've left out any information that may need to be answered to successfully convert this application, please feel free to provide input, and thanks in advance for all who can help me with this.

[Blazer1970]

I know that Parts Mike can sell you the parts you need.

Parts Mike, 750 Perry Ranch Rd, Auburn, Ca 95603 - phone (530)885-0673. Mike

You can call me to buy the brand new shaft and adapter that I stock and sell for $420.00 + shipping. It will require you to disassemble the NP205 and bore it out to accept the TH400 32 spline female shaft and bearing. Call (530)885-0673 Mike

I am sure that he could advise you on the tranny questions also. IIRC, any short shaft TH400 will work, 2WD or 4WD.

Personally, I would just run the TH350.

[ljbear]

Greg,

I don't know about shaft lengths on the Th400, but if you find one from a 4x4 it should have a 32 spline male output and be the correct length. The 205 needs to have the input changed to a matching 32 spline female input, that requires a larger bearing. The case has to be bored for the larger bearing. I bought my 205 input and bearing from Advance Adapter and they are a great source for most swaps like this. Parts Mike is also a great resource when it comes to this sort of thing. His brother Bill built my differentials, transmission, and TC. Unless you own a Chevy dealership don't even waste your time getting prices there, $$$.

Larry

[Gregsmx]

Ljbear, thanks for the input. I'm closer to completing this package now.

I've found a TH400 from a 1989 p.u. It has a 2 1/2" inch exposure from the face of the housing.

I purchased an input shaft and bearing/gasket re-build kit.

Now I just need that hard to find adapter between the TH400 and NP205.

If you or anyone knows a good source to locate this part, please let me know.

Thanks again for your input on this one.

[Gregsmx]

Blazer70, thanks for the no. to Partsmike. I'll give them a call on the adapter tomorrow!

I'm a little afraid of the TH350 strictly from the standpoint that I'm going in with a 475HP 450ft-lb. 427 (454 block, 427 crank). Just wanted to be sure was beefy enough. Secondly the truck is begging for a TH400 since it was originally equipped with the same.

We do crazy things with these trucks sometimes I know!