Kronos, you are correct that the rod is stressed alot on break-in and that is why I bought two Go-Tech rods that are the same size as my 35+21 and Kangaroo motors and use them exclusively for new engine break-ins only. I also use off-road 14mm or 14.5mm cranks in the new engines as well so the new crank-pin on the new crank isn't worn prematurely. After the engine is broken in and no ill pinch, I re-install the unused new rod and new crank back in the motor and off we go. This was the best piece of mind for me since I didn't want to damage my new stuff on the most critical time of a brand new engine.