I have a 20' Hawaiian with a Berk 12jc and a 460. I dont know that the pump has ever been rebuilt. The boat currently runs 65 on a gps @ 5,400. I am wondering how does a pump act when it needs a rebuild, I have a couple impellers that I could use when rebuilding it both are Aggressor's I have a mag bronze A and an aluminum B. What would you guys choose to work best with my boat. What about choices for a wear ring. I hear good things about the ultimate wear rings.