I have a –69 Mach with 351W and a FMX tranny. My problem is that there is so much slippage in reverse gear that the car hardly moves. I tried to adjust the bands and I even sent the transmission for a rebuild but the problem remains. I also disassembled the rear servo but couldn’t find anything remarkable there either. Does anyone have any suggestions? Right now I’m tearing it apart but I’m not really sure what to look for. Please help!