NP203 and TH400

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Kilian

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Right now I have a NP203 mounted to a TH350 in a parts truck. As I consider my project options, would a TH400 that came mated to a NP208 also work on that NP203? Or are there different tail piece and output spline issues between the TH350 and TH400?
 

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The TH 350 and 700R4 is a 27 spline output. The 400 is 32 splines.
 

Kilian

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OK, thanks. Figured there was a difference just as there is for the NP208s.

Are there any differences in the tail piece of TH400, or is it all on the transfer case side? Different adapter, different spline input, etc.
 
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bucket

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OK, thanks. Figured there was a difference just as there is for the NP208s.

Are there any differences in the tail piece of TH400, or is it all on the transfer case side? Different adapter, different spline input, etc.

There's several different lengths of 4x4 output shafts for the th400. The one for a 203 is the shortest.
 

Kilian

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Thanks. Are there aftermarket suppliers of the parts needed to adapt a 400 to a 203? Or is finding original parts the only option?
 

bucket

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What is the goal here? Why not just use the 400 with the 208? Or do you just have the trans and no 208?
 

Kilian

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Have 400 and 208 combo. Doing a 4x4 frame swap and frame came with a 203, which got me thinking of going with a full time setup. Just figuring out what works with what. Thanks
 

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Imho, the 208 is the much better way to go... and the fact that it is already mated to the 400 is an added bonus.
 

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This ^^

That 208 is far superior to the 203. It’s lighter (probably literally half the weight), smaller and the low range gear ratio is lower (2.6 vs 2.0).

I get that you were considering the full time aspect of the 203 but, IMO, the rest of that boat anchor isn’t worth it.
 

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You can run a pto with the 203.
 

Kilian

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Thanks for the input, and will most likely stick with the original plan of using the TH400/NP208 combo.
 

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