The 6.7 Cummins and 6.6 Duramax diesel engines are both reliable and solid, but they do differ in some ways. Here's the ...

Offered in 2500 and 3500 form, a 410-horsepower, 6.4-liter V-8 engine paired with an eight-speed automatic transmission is standard, while a Cummins turbo-diesel 6.7-liter inline-six that makes ...