This is what help states.
This part will need further verification...when I first ran into this years ago I was told from several FHC that the rule was to use male...like I mentioned check this (I am sure it has changed)
There was a time BC (before computers) the public opinion was to do ordinances for both genders, however that is not the policy. If the Gender is not know, is is not wisdom to assume the gender by the name.
Unfortunately assumption of sex is just that, an assumption. We a familiar with a teen age girl named Ezra
Just my humble opinion:
If the name is relatively obvious as a male name and the same as the father's name
then yes - set the gender and get the temple work done.