some notes from a beginner, change rings or change pistons?

[sand man]

as some of you know a blew the 5.3 and bought an LY6 6.0, well, today as i was cleaning the engine and checking the block/ rotating , i found that the pistons have some very low but noticable play when you push them from front to back,
also the rod bearings look like they have a little ware , should i change that too?
the last thing is that the first cam bearing have copper colored spots, change or leave?

here are the pics:















here is the cam bearing



bore was smooth with no signs of ware





the block was in great shape acctulay very slight rust consdering its a 2008 and the junkyard was close to sea!




so what do you guys think?