First question when you have piston slap can you only hear it undertruck or can you hear it just standing next to it?

Second I thought my snout bearings might be going out so I removed belt, And spun by hand sounded good no grinding should I assum my bearings are good?

 

Piston slap can only be heard at around high rpms usually on 1-2 shift. I only get it when the truck is cold.

I am not aware if you can tell if the bearings are by hand spinning them. That qestion may be good for someone who would know!!!