Nov 12, 2018 2019 GMC Sierra 1500 Denali Engines and Specs. The 2019 GMC Sierra 1500 Denali will be available with 5. 3liter and 6. 2liter engines. The base unit 4. 3liter and the new Duramax diesel are not going to be configurations for this truck. An EcoTec3 mill, 5. 2liter C8 engine, is good for 355 hp and 385 lbft of torque.