yes they do... Or at least on a duramax
The 2006 GMC Sierra-1500 has 12 valves.
The 2006 GMC Sierra-1500 is a gas-powered vehicle.
The 2006 GMC Sierra-1500 has a 5-speed manual.
The 2006 GMC Sierra-1500 has overhead valves (OHV).
The 2006 GMC Sierra-1500 runs on regular unleaded.
The height of the 2006 GMC Sierra-1500 is 5 ft. 11.2 in. (71.2 in.).
The 2006 GMC Sierra-1500 has a V6 engine.
The 2006 GMC Sierra-1500 is 17 ft. 1.7 in. (205.7 in.) long.
The 2006 GMC Sierra-1500's turning circle is 40.1 ft..
The rear track of the 2006 GMC Sierra-1500 is 5 ft. 6 in. (66 in.).
The drivetrain warranty of the 2006 GMC Sierra-1500 is 3 yr./ 36000 mi..
The 2006 GMC Sierra-1500 has a 3 yr./ 36000 mi. basic warranty.