Just swap out my stock strut and rotor for performance strut and rotor.

just wanted to know how i can tell if my old strut and rotor is still good. want to make sure before i throw it away. or should i just dump it. has 60K on it.

 

Strut and rotor? You are aware that those are two completely separate items, that serve two completely separate functions, correct? You speak as if they're connected.

Well you should've tested the struts before you removed them from the car, but generally speaking as long as they're not leaking or extremely old, they'll be fine.

For the rotors, mic them out, compare to discard/machine specs, that'll tell you. Also obviously a visual inspection for any noticeable cracks or abnormal wear.