I have a couple of rotors for a 13B but I do not know what year they came from. I have some part numbers this is on one rotor, 4801, 277, 4898. Anyone know how to tell what they came from? Any help would be appreciated.

 

https://www.nopistons.com/forums/ind...howtopic=22992



info is kinda jumbled together, it's a couple threads merged together...