I think the torque number would concern me the most. The stock GM 8.5-inch 10-bolt is almost as strong as a stock 12-bolt. Its ring-gear diameter is only 0.375” smaller than a 12-bolt (8.50” vs 8.375”) and the pinion gear shaft is the same diameter. That said, 800 ft lbs is a lot of torque. Sticky tires and hard launch will almost certainly guarantee your rear end taking a beating.

You could dump a lot of money in this for new axles, after market bearings and input shaft or just bite the bullet and do a 9” or a Moser 12 bolt drop-in built to your exact car for about the same money.

My 2 cents..

Glenn