FryedClutch

I pulled out of my driveway today to go pick a friendup and for some reason every time i would accelerate or decelerate or anything some thing in the drivetrain would make a loud bang went back hom jacked it up and found that the bracket on the back of my tranny that holds the torque arm had the top bolt missing and i called up a coulpe parts stores and they couldnt give me any answers so i need to know the size of this bolt
its the top bolt on the torque arm bracket thats on the back of the M^ tranny in my 94 z28 any respons would be much appreciated
thanx Sean