TH400 X NP203 / NP205-27 SPL

Advance Adapter

Note:This adapter assembly requires a TH350 4wd housing and TH350 coupler!!

The kit is designed to replace a TH350 automatic and adapt the GM TH400 to a NP203 / 205 transfer case. Our adapter plate bolts directly to the back of the TH400 and is .590” in length. The adapter plate is used in-conjunction with the original GM TH350 NP203 / 205 adapter housing and coupler.

The adapter kit includes a new 27 spline TH400 output shaft, adapter plate, linkage rod, bracket, brake yoke & pin, freeze plug, o-ring, fastening hardware, and adapter instructions.

Transfer Case

The NP203 originally coupled to a TH350 has a female 27 spline input. This full-time, cast iron case is made up of 4 housings. It is a chain-driven case with a front housing using helical cut gears offer a 2 to 1 gear ratio. This assembly was used in 1971-79 vehicles.

The NP205 originally coupled to a TH350 has a male 27 spline input. The NP205 is a part time, cast iron transfer case with a figure eight front bolt pattern configuration. This assembly was used in 1971-79 vehicles.

Transmission

This adapter kit is designed for exclusive use with the GM TH400 automatic transmission. The TH400 has a case length of 24.250” and a “Texas-shaped” oil pan underneath it. The factory output shaft has a spline count of 32 spline and had various output stick-out lengths

Bill Of Materials

• GM AUTO TRANSMISSION O RING / 716511
• FREEZE PLUG 1.937 / 716165
• BOLT 3/8 -16 X 1.00″ SHCS ZINC / 723731
• BRAKE YOKE AND PIN 3/8-24 / 716140
• SHAFT- TH400 OUTPUT / 52-3200
• ADAPTER- TH400 TO REPLACE TH350 / 51-1800
• BRACKET- TH400 TO NP SHIFTER / 715512
• ROD- LINKAGE FOR 711032 / 715511