Due to a worn down lift, I am pulling the motor down (350). It seems that I may have excessive wear on the thrust bearing. When I went to pull the harmonic balancer, I could move the crank in/out more than I am comfortable with, so I decided to yank the whole thing and take a closer look (and to make the cam replacement a bit easier). The engine has about 4000 miles since being rebuilt. The crank was turned 10/10. I plan to check thrust tolerances with a feeler gauge. Is there anything else I can do? What should I look for?