Do u have a FSM? Look in the specs section. It will show what trucks they were optional eqpt for. I dont think they are std in anything. Also, it will show the gear ratios. As I recall, no 540 is listed with OD. If its loose, just put it in 4th gear, turn the input shaft 1 turn and count the output turns. Most likely will be 1:1. If not loose, turn the engine one revolution. Im quite sure the bell is the same as the 4 speeds.