I now have a 6" plate ... when I plane, just before I crest over, I have a bit of vibration so I had to let off the throttle just a bit and then after it planes, throttle up again. I think it's from the backwash of the prop vibrating against the transum ... question is if I put in an 8" jackplate, will it help with this vibration?? Would it give me any extra speed also?? I'm running a touch over 73MPH by myself (still had a bit more throttle left; but walks like crazy) ... comments welcome here or email me at 5littlebass@gmail.com. Thanks.