Baumann TCS The OptiShift Transmission Control System The existing transfer case will bolt up to the E4OD, However you'll need to modify or get different drive shafts due to the E4OD being longer. The speedometer can be driven by your transfer case yet. The VSS is located in the rear axle. If yours doesn't have a sensor on the top, you'll need to swap to a newer axle with the tone ring and sensor. You'll need to move the trans crossmember back a few inches to match the new trans mount location. You'll need to convert to a TPS on your IP instead of the VRV as well, and shifting linkages may be different.