Bad scuffing right? but only on cylinders 5-8, the other side looked normal. As I dug deeper, I found the rod bearings, only 5-8, had heavy wear on the radius side of the crank, everything else was normal and clean. With this info, I called the machinest and he was equally confused until he asked me which way I installed the pistons on that side. Of course I had installed them correctly but quickly realized that he had installed the rods backwards with the rod chanfer inboard and I did not catch it when I put it all together.
This led to the rod binding and piston scuffing. One Catastrofic problem waiting to happen and vibration source found. On to the second cause. The pistons were much lighter than the stock ones, which could have caused a very small issue but really shouldn't have been felt.