I did hours of research and made a ton of calls on this and could not get one straight answer ( calling Nitro is worthless). I just added an Atlas Hyradulic to my Z8 and I will never own another boat without one. The only way I could figure this out was when I called TH Marine. My boat came with a 10" and I was told if I installed the 12" I would have cleaner water etc. The performance is amazing! Whether that be handling, running, getting on plane or even raising it up to trailer. Hands down the best upgrade I have ever done to any of my boats.