Reverse Lock-out ??
Reverse Lockout
The T56 uses an electically activated reverse-lockout solenoid that prevents the inadvertent selection of Reverse gear. The solenoid is located directly below the shifter. In the factory system,the computer powers the slenoidto allow selection of Reverse only when the car is traveling less than 5mph. While it is possible to "crash through" the lockout mechanism with brute force, the best way is to use a momentary push button switch located on the shift know that will power the solenoid whenever the button is depressed. Wirin the switch is easy, with power reacing the switch from the button while the other side of the solenoid is wired to ground. If you want to use the factory connector, the Chevy part number is 12101857.
Another interesting point that it brings out is that the T56 uses a synchronized reverse gear, which means it can be shifted into reverse with the car moving forward withoug grinding gears. but i would never try or recomend shifting into reverse while driving forward unless you know what your doing
this should help you
if it does not what many of the mustang guys do with T56's is wire it to the brakes, as normally your going to have your foot on the brake,when going into reverse.
not the best way, but for a no hassle method, it works well for them.
Ryan



