I think you'll find that most of the hoses can be simply replaced by inside diameter measurement (i.e.: the diameter of the pipe that the hose fits onto), and the length. In many cases, you'll probably find that a hose of superior quality than your old original hose is available.
The only time it can get tricky is if you have a molded hose with a specific turn to it or an angled end. Even then, often a hose that's close can be found to replace it. Fortunately, most of the strange shaped hoses are usually those that are part of the engine, such as from oil cooler to engine block, etc. Those hoses are usually readily available from Cummins, although they may have to be ordered in to get them.
Jim & Kate
2016 Creekside 23RKS, 2014 Ram 1500 Eco Diesel
1995 Monaco Dynasty 36', 2005 Honda Pilot