YES they are the same.
NO
85 mph.
The 2011 Chevrolet Silverado-1500 has a V6 engine.
The 2008 Chevrolet Silverado-1500 has a V6 engine.
The 2007 Chevrolet Silverado-1500 has a V8 engine.
The 2014 Chevrolet Silverado-1500 has a V6 engine.
The 2003 Chevrolet Silverado-1500 has a V6 engine.
The 2014 Chevrolet Silverado-3500HD has a V8 engine.
The 2013 Chevrolet Silverado-2500HD has a V8 engine.
The 2002 Chevrolet Silverado-2500HD has a V8 engine.
The 2012 Chevrolet Silverado-2500HD has a V8 engine.