I have a 1999 Ox66 250 25". I have been thinking of going to an HPDI 250 and have a lead on a VMAX 250 HPDI 20". I am thinking that because the VMAX has the factory low water pickup that I'll be able to get away using a 20" motor instead of a 25". Any thoughts on this? Also, what rigging would need to change to go from Ox66 to HPDI or is it plug and play?