If you are going to go through the trouble to convert over to a mixed flow pump i.e. Berkeley/Dominator because you want to gain performance you would be much better off doing a little more glass work and putting in a jg Berkeley or 12 S Dominator split bowl non-insert style pump. You are going to have to do some glass work anyway and I don't think you would really gain all that much if any switching from a Panther to a je/jf insert type pump. How much horsepower are you planning on running and what type of boat is it in?