A Cummins engine's internal ... cfm is being achieved on the intake, which is quite a lot. These fully ported heads are being used on today's 2,500 to 3,000hp 12-valve Super Stock pulling engines.

The stock fuel system, air intake, and exhaust are all designed around the 5.9L Cummins engine’s 215hp rating, and they will all be restrictions on the powerplant as horsepower and torque increase.