So both the sets of rotors are from a 87 NA but they don't look the same. mine still have some of the gold color on the faces. Does it make a difference? what are your opinions? Mine is on the right

 

i would take the pair that came out of a factory built motor.

 

you canNOT tell if a rotor is good by its "color".

sure if its fuzzy color it might be overheated, but the only sure way to tell is to measure it.

 

they were both out of 87 na stock motors
why do they have different dimples?

 

the rotor is cast, castings vary in weight/balance. the factory balances the rotors, and the "dimples" are where they drill to remove weight to get the rotor to balance.

then they take the rotor BATCHES and grade them for weight. so they take similar weight rotors and put them in an engine.

so you should use the pair of rotors that left hiroshima together.