I have a 426 that I bought a few months ago. It had an oil blockoff kit installed( wet sump), but I returned it to a dry sump with the help of all you guys here at TT. Thanks again for all the previous advice. The bike starts first kick and runs absolutely perfect and is killer fast. The problem is that I don't know how much time it has on the top end, and I'm by nature the type of person who doesn't like to take unecessary risks. The questions I have are, 1.) What are the odds or is it possible that the piston might be larger than stock and if so, how do I identify the size? 2.) Is there anything to watch out for during the top end replacement? Are there any steps or advice that anyone has which might save me money or heartache during the process? 3.). Is it relatively basic, that someone with the right tools, service manual, and a decent mechanical skills can perform? 4.) Are the main parts I need the piston pin, clips, rings, piston and gaskets? Oem best?? Thanks in advance for any advice. I will document everything and post the results.