Adapter Kit – Cummins B-Series 4BT / 6BT to Tremec TR-4050

Adapter Kit – Cummins B-Series 4BT / 6BT to Tremec TR-4050


Bell housing adapter kit combining the Tremec TR4050 to Cummins 6BT.


The Quick Draw Adapter Kit for the Cummins B-Series to Tremec TR-4050 provides an clean and convenient way to mate a great engine to an equally great transmission! This adapter kit bolts the Cummins 4BT or Cummins 6BT to the Tremec TR-4050 5 speed transmission.  Most people already know the benefits of Cummins B-Series engines, but not everyone may be familiar with the new Tremec TR-4050. The transmission is a major upgrade over the popular NV4500 as it shifts like a car, weighs 100 lbs less than the NV, and is rated at 600 ft/lbs of torque at 15,000lbs!

This adapter kit bolts directly to the 1994 to 2007 Dodge flywheel housing / starter plate from the Ram 2500 and 3500 pickup trucks.  Please note that 1989 to 1993 Dodge flywheel housings will not work with this kit.

Our Tremec TR-4050  to Cummins 6BT adapter kit uses the Dodge Starter and the 1994 Chevy 1 ton Clutch (Part #K70188-01HD), both off the shelf parts from any local auto parts store.  PLEASE NOTE: The pressure plate / clutch cover must be rounded on the edge, not the square edge style (see photo).  Our adapter kit moves the starter to the drivers side for more exhaust clearance (unlike some of the problematic factory 4BT bread van adapters).  We recommend using both the master and slave combination from a 1999 Jeep Wrangler 4.0L.  This has been proven to work by simply modifying the connection from master cylinder rod to clutch pedal and using  one washer approx .080″ thick top and bottom between the bell and slave.

This is not a complete installation kit but includes the everything needed to bolt the Tremec TR-4050 to a Cummins 4BT or 6BT turbo diesel engine.  Looking for the Cummins to Chevy SM465 adapter kit?  Click here.

Cummins 4BT / 6BT 4BT Adapter Kit Includes:

  • Bell housing for the Tremec TR-4050 – B-Series engine
  • Flywheel drilled for the Tremec TR-4050 Clutch pattern with oiled bronze pilot bushing
  • HD clutch fork, pivot ball, and throw out bearing.
  • Hardware to bolt the bellhousing to the engine and transmission


All TR-4050 6bt and 4bt kits will ship FedEX with signature required at delivery.

Additional Info:

If interested in purchasing the transmission with this adapter kit click here.

Here is a promotional video showing the toughness of our bell housings.  Some photos showing engine and transmission combination are for representation.


Additional information

Weight95 lbs
Dimensions18 × 18 × 8 in