Have a aerator pump leaking into bilge. It leaks where the motor goes into the top cap. It has an o'ring which I'm trying to find a new one. It has a 1/2 discharge at 360gph all the new ones have a 3/4 discharge at 500gph. Two questions does anyone have a old one with 1/2 discharge. Also if I went to the 3/4 500gph would the system be able to handle it without blowing things a part. I know I would have to add fitting s to reduce it from 3/4 down to 1/2. Thanks in advance.