Thats correct. With the kawi pumps you need to replace the whole thing. They do not have separate sections like yamaha. A mag pump will not help with low end, just hook up. Honestly the pro is the worst low end / least playful hull out there. To get more low end you are looking at replacing the motor. SP will have better low end, 701 will have the best. Problem is you are still building on a hull made for carving buoys. Best best is to sell the pro to someone who wants one for what it is, and start on a superjet or a SX hull.