Did you mark the rod before you tore the engine down??? Sometimes if the rod and piston don't go back in the same way it came out it could rub on the case A little. I have seen A lot of rough machining inside A case that looked like there was A problem but there really wasn't but you said you can both see and feel it hitting, that leads me to the rod and piston going back in the wrong way. 30 flights should not bother A bearing at all. However, stock OS bearings do feel loose and rough right from the get go, it even says that in there rebuild book I have. Off topic A little. does the new Boca Bearing you got look exactly like the one you pulled from the engine?. I used Boca on my last rebuild and they were different and I had to pull the sheild off the front and the rear had no seals, Boca said these were correct but OS said no way?? I didn't worry about the rear bearing but the way the front bearing was sealed made the engine run real hot very fast until I opened up the engine again and removed the seal. Just wondering if your bearing looked just like the stock one you pulled?