Yea- Cummins uses an intake heater, which works pretty good. Simple and failsafe.
It isn't uncommon for a diesel to be hard to start in cold weather- what are you calling "hard"? You may have a problem, but it would help to know how hard of a time you are having, and what is routine hard starting for a 6.5? You may just be getting used to a diesel, and not really have a problem.