I am the current owner of an RV6A that was built by another. The plane flies great and I have close to 200 hours in it since purchase last April. There are a few things I want to change (imagine That), One of which is the fuel selector valve. The current one is not the smoothest and you have to position it in the off position as you change from left to right. I have also had it reposition itself in flight resulting in an engine shut off. Obviously got it repositioned and the engine started and then fixed the loose nut. At Sun N Fun I saw the Andair valves and loved the smooth action of the valve so when I saw their booth at Oshkosh I took advantage of the show special and got one. I talked to Andy (The Guy in the booth) about the retrofit and he was pretty sure it wouldn't just slip in. So was I by the way. He recommended flexible steel braided fuel lines to attach the valve to the existing lines. That makes a lot of sense to me, but I haven't seen anyone using them on this forum in fact some of the "spaghetti bowl lines" I have seen lead me to ask why wouldn't you use flexible? Is there something I am missing?