spindles - same 65-68?

I have a 65 and a 66 stang and what I believe to be are front spindles from a 68 mustang. From what I can make out, the codes on all of them seem to range from c3 to c6***. Can I use 68 V8 spindles on a 65 or 66 mustang- are they are direct replacement as far as bearings, drums etc are concerned? Whats different? These are non-k-code cars but I doubt that makes a different if your just talking spindles and not drums. I welcome anyone thoughts- Thanks.