I uploaded those Ken Smith articles on the Dutch Model Club site years ago. They were all scanned in.jpg format and should have no problems downloading.. A Freightliner FLC brochure I have, which mirrors many photographs and information from the Testors Freightliner FLC kit confirms that it is indeed a mid 1980s Cummins NTC350 engine.
When it comes to detailing engines, I always refer to brochures and repair manuals. The internet is full information. Every engine's set up is different based on the type of truck, the options, engine requirements, etc. And of course the final reference is an actual engine in the type of truck you are building.
This is a photo of a R&C Resin Cummins L10 I am detail for a Ford Aeromax 106.