Just check the size and run lengths (back and forth, i.e., x2). Otherwise, it's pretty simple. I've changed-out two old PAR reciprocating pumps (one one the Sabre and one on the J/Boat). The first Shurflo is probalby still running from over 18 years ago for the Sabre's current owner. The J/Boats old pump had a simple pressure switch issue, and I summarily replaced it with a Surflo over a decade ago -- it's still running like it was new.