The quad cab has a smaller back seat and a larger bed, the crew cab has a larger back seat and a smaller bed. To compare them you can go to http://www.ramtrucks.com/en/2011/ram_150... and select the Build My Own option from the bottom of the page.
Heart muscle thickening (called cardiac hypertrophy) can be a healthy response to exercise and pregnancy; however, it often occurs in people with high blood pressure, diabetes, heart failure and certain genetic conditions.
What Is an Enlarged Heart? An enlarged heart is an abnormal increase in size or thickness in the heart muscle, often causing the heart to pump blood inefficiently. Although an enlarged heart is not an actual illness, it is a symptom of many heart- or blood-related illnesses.