The Advance Adapters TH400 2.75" to Atlas Adapter Kit (SKU AS-6440) is built for the GM TH400 automatic transmission — a 24-1/4" case with 13 bolts holding the oil pan, available across three different engine-to-transmission bolt patterns, so confirming you have the right TH400 for your engine is a necessary first step before ordering.
The rear of the case uses a hex-shaped, 6-bolt pattern, and the TH400 has shipped with several different output shaft lengths over the years. This particular adapter is built for the 6.9" overall shaft — once installed, that shaft sticks out roughly 2.5" from the transmission, which is what the "2.75" in this kit's name refers to.
What's included:
- Adapter, TH400 to Chrysler Jeep (51-6440)
- Plug, 22mm Reluctor Sensor Plug (716079)
- GM Auto Transmission O-Ring (716511)
- Bolt, 3/8-16 x 1.25" H.F.C.S. Non-Serrated (301410)
The "Chrysler Jeep" adapter designation means this kit is built for coupling the TH400 into a Jeep-based Atlas swap. Because the TH400 comes in multiple bolt patterns and output shaft lengths, double-checking your specific transmission's shaft length (6.9" overall, ~2.5" stick-out) against this kit before ordering will save a fitment headache.