The first track day since the spring is coming up and I was going over the car and noticed that there were fibers hanging out of the rubber coupler and the rubber was cracked.
It turns out that GM doesn't list a part number for the coupler, it comes with a complete driveshaft. If you have the correct part number, you can get couplers but the number is not easy to determine. My parts guy didn't have a part break down of the driveshaft assy and couldn't look at the coupler "where used".
I found this thread
https://www.camaro5.com/forums/showthread.php?t=554318 after I ordered wrong couplers
The correct number for 5th Gen SS & Z28 manual cars is 92228328.
There are single use components on the drive shaft:
Nut, Propeller Shaft (6ea) 92228333, (also coupler to trans, 3ea), 1 Use
Washer, Propeller Shaft (6ea) 9222834
Bolt, Propeller Shaft (6ea) 92228335 (coupler to shaft), 67 lb-ft 1 Use, measure torque on nut
Bolt, Propeller Shaft (3ea) 92139104 (to differential), 85 lb-ft 1 Use
Bolt, Rear Propeller Shaft (3ea) 92139225 (to transmission), 72 lb-ft
Bolt/Screw, Propeller Shaft Bearing Support (2ea) 11515758, 192 lb-in