Here\'s the new pump hiding down there where the old one was. I fastened the ground wire to the radiator frame at left, where I also grounded the supplemental vacuum pump. The pressure switch (a Furnas 69MB7) is in the middle of the picture--I had replaced that last year. The bottom line: The new pump fills the tank only, from dead empty (0 psi), in 90 second, tops. It will fill empty air bags and the tank in three or four minutes to travel level, and in 7 or 8 minutes to 125 psi maximum rear height. Those times ranged from 7 or 8 minutes to 20 or 25 minutes with the Dana. The Viair will fill the tank from 80 to 125 in less than a minute. The pump is rated for a 100% duty cycle at 100psi/72 degrees, so it is certainly up the needs of the GMC. The pump is reasonably quiet--quieter than the Dana but still audible from the driver\'s seat when the engine is idling. Total installation took about two hours.