Unequal samples sizes and post-hoc tests

Hi, I am conducting an ANCOVA on three groups one of which is twice as large as the other two. Am I supposed to use Tukey-Kramer as my post-hoc test? If so, there is no special selection for Tukey-Kramer in SPSS. Is this automatically calculated in the output if Tukey is selected? If so, where? Also, how does one report the results? Any info would be most welcome. Thanks!