These are the parts for the 10/12 bolt build up for the rear diff.
The Corvette rear end has mostly 10 bolt spiders,cross shaft, posi case etc. from the factory. The posi case/ ring and pinion have both been cryogenically treated to change the metallurgy, and make them stronger. Cost 150$.
The posi case has been polished to eliminate stress risers, which can cause cracks, and the ring gear surface will trued up.
When these units fail, its usually the posi case that cracks, so strengthening that anyway possible is a good upgrade.
The spider gears, axle drive gears, and cross shaft, will be upgraded to 12 bolt heat treated parts.
The unit will have precision fit clutch paks, eliminating the retainer spring set that is stock. The carrier cap on the left will also be replaced with a precision fit steel cap and 1/2" bolts to eliminate the carrier trying to push out of the housing on heavy footed escapades. The right cap will have upgraded bolts. The ring gear bolts will be upgraded to ARP's which then have to have the head turned down to fit in the housing.
The axles will be upgraded to Tom's 31 spline K/A flanged axles, that will be hardened.
This will be a trick piece when done....