Depends on if the car is an SS or a Non-SS. Non-SS's used U-bolts, lockwashers and nuts to hold the rear universal to the rear yoke. SS's and Z28's used a strap and two bolts to hold the rear U-joint to the yoke. Not sure if this is a 10 bolt vs. 12 bolt axle oddity, but it's identified in the RPO L48 section of the assembly manual. If you have a 12 bolt you may find the straps instead of U-bolts even if the car isn't an SS.
The U-bolts are P/N 1358938, lockwasher is P/N 103320, and nuts are P/N 102634. The straps are P/N 3882979, and the bolts are 3887348.
