I'm not sure you fully understand how the overdrive works in a 700R4. The cable and the adjustment is critical on these transmissions. It controls the shift points not only the overdrive engagement. If the cable is not adjusted correctly you could damage the transmission in a very short time.
The 2004R trans was basically used in smaller engine applications, V-6's and small V-8's. It is about 4" shorter than a 700R4. It can be built to accomodate more torque. The 700R4 was used in trucks and larger cars. The electronic version is a 4L60E which came out in about 93.
Fred
