I figured out my pulling power problem on 16's. Factory tune is only 515 hp but it's now bumped to a CAT tune on the C15 at 625 hp and 2,050 ft. lbs. of torque which is about as much as a stock C15 on sequential turbos will put out with only a plug and play tune. Brakes are fine as they are full air brakes on this rig. The tune up helps when hooking to other similar sized trucks and grossing over 100K on big tires.