The pump on my Devilbiss air compressor was tired and it was time for a replacement. After some internet searching and pump pricing I decided on a Rolair (chinook) K-30 pump. I offset the compressor on the tank top plate rather then make new adjustment slots for the motor. It's a 60 gallon tank and its powered by a 5 HP. 3450 motor. The new pump is half as loud as the previous pump and has more cfm., it displaces 21 cfm and has 17 delivered cfm. with a pump RPM. of about 850.