Hello all, jmk here and I have a question on the water pump cavity for my 1971 55 hp. Last year when I took the pump apart the wall on the inside of the pump where the impeller rides was just aluminum cast. It was all pitted. I lightly sanded it and with a bad feeling I put it back together with a new impeller kit. I thought that I saw somewhere where they were selling stainless sleeves to insert into the pump for the impeller to ride against. I am I wrong, or do they sell them? Where can I get one, and if not what is the best solution to fix it? That impeller only lasted maybe 50 miles, and now it's shot again. Thanks jmk 