I have a 93 35' lighting, the boat had 465hp in it stock w bravo's w 27p Hydros, ran about 81 or 3 on a good day. Well I had the great idea to rerig the boat, I built NEW dart 540's opened to 557ci, w AFR 315 heads Calias cranks and a indisclosed cam that the builder chose, we made just short of 800 hp at 6500rpm. I will run the boat to 5500 rpm where the motors make 720 or so w 700 ft/lbs of torque at 4200rpm. We put stelling boxes on w the drive mounted in the highest position which is 1.5" over stock, as well as a 2" imco shortie. Tonight we put the shorties on the XR's and the shorties came with a polished cavitation plate the mounts to the top of the cavitation plate on the XR, it appears the only reason for the plate is to mount the drive shower back further........is this true???? and will it hurt any part of the driveability of the boat if I run without them???? I have 30p 5 blade merc maximus wheels i'm going to try on the boat, Thanks.