50-6901 : GM 700R4 to GM NP208 Adapter Kit (replacing TH400) (#50-6901)

Retail Price: $515.00

Advance Adapter

The GM 700R4 main shaft kit is used when replacing a TH400 in model years 1985-91. Once installed into the 700R4, the output side of the 700R4 looks identical to a 4WD TH400 that is being replaced. The adapter kit includes a new output & spud shaft, plastic washer, adapter plate, TH400 gasket, o-ring, metric fastening hardware, and adapter instructions.

NOTE: This kit re-uses the TH400 adapter / 4wd tail housing.

Transfer Case

The adapter assembly fits 1985-91 GM NP205 / NP208,241 transfer cases that were previously used with a TH400. This adapter assembly requires that use of the original GM TH400 4wd adapter. These GM transfer cases features a 32 spline female input shaft, and a circular-six front bolt pattern.


This kit is designed for exclusive use with the 700R-4 / 4L60 / 4L60E. The overall case length of the transmission is 23.375", has non-removable bell housing, and a 4 bolt square rear case. Late model 4L60E automatics will have removable bell housing and a 6 bolt hex pattern rear case.

Note: The late model 4L60E automatics will require VSS kit.

1. GM New Process 205

2. GM New Process 208/241

3. GM 700R4 & 4L60

4. GM 4L60E

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