I'm looking to convert my diaphragm type lift pump on my '89 to a piston type pump. I've read through the sticky's regarding converting from the diaphragm type to the piston pump, and I am having trouble locating a low pressure pump.The local Cummins dealer has one that matches the part number in the sticky, but they want $270 for it! The pumps for '94-'98 are plentiful, but from what I've read they put out too much pressure. Any help is greatly appreciated!