this tranny is from the firebirds and camaros with a 6 speed tranny. it is too high of gearing for use with a normal z. great for a v-8 swap. if you do use it, you will need a custom belhousing made, and a 4.11 or 4.32 rearend, in ordr to compensate for the tranny. you also have to modify your driveline tunnel in the car. it is also heavier, and IMO a waste of time for a L28 engine.