The Ford C6 Transmission is an automatic transmission that Ford used as a replacement for the C4 transmission in about 1966. It has no electronic controls, so it is popular with racers and restorers today because of its simplistic design and low cost.
The C6 transmission does not have overdrive gears and lockup torque converters, so it may not be as fuel efficient as more modern versions. The C6 is virtually the same on the inside as the C4, but it is a larger version meant for more heavy-duty usage. Ford developed a C6 for diesel engines in the 1980s and continued its production until the mid-90s.