I am only basing this from tearing down a TT engine and an NA engine recently. The rods on both engines were marked 1-6, front to rear. This would lead me to assume that something has been done with your bottom end at some point and time unless there was a factory mess-up. Hopefully one of the experts will chime in. As far as the bearings, I'm not at the point of rebuilding yet but I am curious about the bearing grades as well as this is my first TT engine build. Good luck!