I'm confused. Doesn't your engine have its own water pump? Or were you using the Jabsco impeller to get a bit more water flow in the system?
Jabsco and Johnson impeller pumps are fitted to many/most modern marine diesels as the raw water pump. They seem to be the popular choice with marine conversions as well due to price, availability and ease of fitting.
Why on earth do people use these things? Do they have any advantage over a centrifugal pump. They certainly seem to have reliability disadvantages!
I changed four impellers on the engine and about five on the generator over a 13 year period on my last boat. In fairness though several were changed as part of an annual maintenance regime, since changing an engine one at sea was guaranteed to spoil your day.
Sadly for the price there is little to replace them so remain the modern popular option. I was always careful to turn the engine over in normal direction when adjusting tappets though to avoid bending blades back on themselves.
Currently the gear type pump I have seems very reliable and coming up to eighty years old!