Can some please tell me, if I change from a 15-21 deg pitch to a 14-21 deg what would happen? I am not real sure how the pitch of an impeller is sized? Is it for the weight, performance, Horse Power. I have several impellers here for seadoos 271000416, 271000282 & 271000046 as for the last one I can't find any data on it at all. Could some please help with this?