That piece of hose for a spacer is really a pretty genius idea. But it says that someone had the differential apart sometime in the past.
I'm wondering how you pulled the driveshaft without pulling the differential apart, as the pinion needs to come out the back. Personally, I would have pulled the torque tube/differential assembly and thrown it on the bench to avoid having to work under the truck to reinstall the pinion and differential. I pulled mine out to restore the gasket, basically fixing leaks, and it wasn't hard at all. Granted, I was just working on a bare chassis, but still.
You may have a hard time getting the driveshaft stabbed back into the bushing at the front of the torque tube with it under the truck, and may wind up pulling the differential housing and torque tube anyway instead of fighting with it underneath the truck.
Good luck.
