Does a 2003 Kountry Star have a CAT C7 engine?

http://www.irv2.com/forums/f101/cat-c7-fan-hub-failure-79162.html

I had looked at a few Nemar DS in that age bracket but was also afraid of the fan failure. From what I can understand, the C-7 used in conjunction with a rear radiator was the problem. I understand, the fan hub would loose its bearing and the fan would come lose, sometimes destroying the radiator.

My 03 has the Cummins 5.9

In 2004 Cat. engines went to a sealed non-greasable fan hub bearing.
Prior years they had a bearing with a zirk fitting on it that you lubed.
The later sealed bearing did have some failures.
The Cat. engine in the Kountry Star you are looking at should have the GOOD bearing and of no concern, if it does have the Cat. engine.
This bearing is often overlooked in maintenance because it is only accessible from the top of the engine.
On mine, I lift the bed, remove the metal plate over the engine, give the bearing 4-5 shots of grease once a year, no big deal.
When you take it in for a lube job, only the best techs know its even there, or want to take the time to do it.
I was on the road awhile back, stopped at a Camping world, and got their oil change and lube job. Expecting to take care of the fan zirk myself later
After a bit the tech surprised me. He said would you mind lifting your bed up so I can get to the top of your engine for the fan bearing zirk. You never know.
To answer you question
It most likely has the 3126e 330hp Cat. not the C7 350 hp Cat. engine.
The C7 engine appeared in the 2004 and later year models.
The engine serial number and a call to Cat. customer service will verify it all to you.

A 2003 chassis could have either a Cat 3126E or C7.

Call Caterpillar with the engine serial number and they can tell you which it is as well as whether it has the sealed fan hub bearing or the greasable one.

877 777-3126

Look at your valve cover as a C7 will say Acert and will not have a breather coming out of it. The breather will be on the LEFT side as in a truck with the engine facing forward. Hopefully it's not a early C7.

Mine was a sealed bearing, I changed it over to a grease able one

posted a pic but its not showing up