Spindle ID tag "help"

[mjgord51]

I am thinking of buying a set of Drum brakes complete form the Spindles out to the lug nuts, Person selling them says they come from a 70 or 71 C10. ***There is only a tag wrapped around one of the tie rod mounting end with the #'s KQ 3970910 ***, I know other spindles ( newer) ones have casting #'s on them, these have no casting #'s that's why I am asking this question, any help will be appreciated, Thanks in advance, mjgord51 ( Marvin)