Vortec 5.3L aluminum-block V8 engine features:

From the family of redesigned Gen IV Vortec V8 engines
315 horsepower @ 5200 rpm
338 lb.-ft. of torque @ 4400 rpm
EPA estimated 16 city/20 highway MPG in 4x4 models
Standard Hydra-Matic four-speed automatic transmission
Lightweight — yet strong — deep-skirt aluminum block
A cast-iron crankshaft with undercut and rolled fillets
Cast-aluminum cylinder heads that feature a low-friction roller-rocker valvetrain
Electronic Throttle Control provides outstanding throttle response, greater reliability and improved efficiency
A faster, smarter Engine Control Module with more memory that better synchronizes the multitude of engine operations that occur every split second
A thermoplastic composite intake manifold that helps keep the air intake cool. And equal-length runners feature smooth interior passages to promote high-speed airflow to each cylinder
Hydraulic engine mounts for improved vibration isolation
A coil-near-plug ignition system for a precise delivery of high-energy spark
A coolant loss protection feature allows the Silverado to be driven a limited distance at a reduced speed in order to reach a service facility even if a catastrophic reduction in the coolant level has occurred
Extended-life spark plugs and engine coolant