installed my t56 yesterday and noticed a different wiring harness clip on the side of the trans different from the stock 5spd. anyone know what it is and what is needed to hook it up?
That is a reverse lockout solenoid, it is used to help prevent reverse from being accidentally engaged. It is possible to force the shifter into reverse without powering up the solenoid, but it is very difficult. The solenoid needs to be wired into a 12 volt power source that will only power it when the brakes are applied, or to a switch that can cut the power to it except when reverse is needed. On factory 6 speed cars, the solenoid is activated by a signal from the engine controller.