If you are talking about the small block V-8 Chevy engine, there is a small flat pad with an engine id number located on the block, in front and below the passengers side cylinder head. Using that number, visit web Chevrolet engine identification sites to determine which engine you have.
Try mortec.com
The 2013 Chevrolet Corvette has a V8 engine.
The 2006 Chevrolet Express has a V6 engine.
The 2011 Chevrolet Express has a V8 engine.
The 2012 Chevrolet Camaro has a V6 engine.
The 2012 Chevrolet Express has a V8 engine.
The 2002 Chevrolet Express has a V6 engine.
The 2001 Chevrolet Express has a V6 engine.
The 2007 Chevrolet Express has a V8 engine.
The 2013 Chevrolet Suburban has a V8 engine.
The 2012 Chevrolet Suburban has a V8 engine.
The 2009 Chevrolet Express has a V8 engine.