I would not bastardise a 4.9 to do it..... Too much $$$, devalue the boat and cut you off from any 4.9 class racing. Even if I was to build an F16 using Taipan hulls in AUS, I would follow the 4.9 class rules. If outside AUS or building a new F16 from scrath, then I would go max beam, even on a 4.9.