Some good info on the GM 8-Speed 8L90 M5U Hydra-Matic Automatic Transmission
"New 2016 Silverado 1500 pickups with the 6.2L V8 engine will get a new 8-speed automatic transmission. The new transmission will also be standard on LTZ, LTZ/Z71 and High Country Silverados with the 5.3L V8."
GM 8-Speed 8L90 M5U Hydra-Matic Automatic Transmission
The Hydra-Matic 8L90 (production code M5U) is a fuel-saving and electronically controlled eight-speed automatic transmission developed and produced by General Motors for use in rear- and rear-biased all-wheel-drive vehicles with[...]
gmauthority.com
"New 2016 Silverado 1500 pickups with the 6.2L V8 engine will get a new 8-speed automatic transmission. The new transmission will also be standard on LTZ, LTZ/Z71 and High Country Silverados with the 5.3L V8."