I'm assuming you mean "525" as a horsepower rating, and not as a model number, and you're probably referring to the 525 horsepower rated N14. All the Cummins I6 engines use 1-5-3-6-2-4 as their firing order.
1342
if it is a cummins, the order is 1,5,3,6,2,4
The firing order in an 8 cylinder Cummins engine is normally 1, 8, 4, 3, 6, 5, 7, 2. The order should be stamped into the metal of the engine.
The firing order should be 1-5-3-6-2-4.
firing order of 4 Cly engine - 1 2 4 3 ..
1-5-3-6-2-4
The firing order is 1-5-3-6-2-4.
From the factory, 525.
1-5-3-6-2-4
From the factory, it was available in ratings from 350 to 525 horsepower.
Firing order is 1-5-3-6-2-4 with a tappet clearance of .010" intake and .020" exhaust
Trick Question - There is no Firing ORder since its a Diesel Engine! Ha! Actually the firing order is 1-5-4-8-6-3-7-2 for a right hand rotation engine. All engines have a firing order, diesels fire from compression versus spark for gasoline/propane and the like if there's no firing order, the engine will be as useful as a boat anchor.