Overdrives based on the 727 are called RH46 and RE46

Rh is hydraulic governor...RE is Electronic governor that is shifted by the PCM...

Overdrives based on the 904 are RH43 with the H being Hydraulic controlled governor.

Tony

70 AARCuda Vitamin C
71 Dart Swinger 360 10.318 @ 128.22(10-04-14 Bakersfield)
71 Demon 360 10.666 @122.41 (01-29-17 @ Las Vegas)
71 Duster 408 (10.29 @ 127.86 3/16/19 Las Vegas)