Ok... so mains is bearings? I couple of the guys I work with thought it might be a bearing too.

Oil is fairly new, about 50 miles, and it was conventional.

Is rocker lash the same as a valve adjustment? This is what I planned to do this weekend: http://chevy.oldcarmanualproject.com/shop/1948_51truck/51ctsm0607.htm

I am assuming if I pull the oil pan I am able to see the bearings?

Sorry for all the questions, I just want to make sure I understand everything.