Trying to do the same thing on a 19 Z71 with 3.23 diff. These are the parts I got from a dealer for stock assembly with 3.73 gears. The catch is that since they can't match to your VIN, there's no returning if it doesn't work. Now who has the balls ($$$) to give it a shot!
https://www.gmpartsbin.com/p/Chevrolet_2019_Silverado-1500-LT-Extended-Cab-Pickup-Fleetside-53L-EcoTec3-V8-AT-4WD/Differential-Housing-Front/75803041/84446296.html
https://www.gmpartsbin.com/p/74589573/84496944.html