Ask for their Letter of Approval
You might want to ask Cummins what they think about putting the Walker AirSep on their engines. I have a fleet of the larger engines (11 to 38 liter) and Cummins clearly states in their manuals NOT to use that system. I went ahead and put one on a 38 liter engine and over time, even doing the proper maintenance the oil vapors covered the air cooler, and everyone knows that doesn't help heat transfer at all. I asked the Walker rep to show me their letter of approval from Cummins to use their system, and he suddenly found someone else to talk to. Just food for thought.