What is a common practice when tolerancing for a heim end. This would be for a spherical, aircraft type. I assume a .010 per side tolerance to the receiving end; which is a clevis type receiver.
I think you're referring to the mating width between the rod end and the clevis heim? The MIL-STD rod mating end widths are more likely to be +.000 - .005 and the clevis heim +.005 -.000. If not tighter - aircraft components are generally built to more controlled standards than automotive or industrial applications.
I would assume that you are designing an installation and have already picked either end of the rod or other assembly. I would consult the associated MIL-STD or AN standard or specification and determine the recommended tolerance structure for the installation.