Which Machop should I evolve?

I kind of got back into Pokemon Go pretty recently and didn't know much about IV's before that. I currently have two machops that are decent:

Machop (88%) - 157 cp - IV(15-[9-10]-15)
Machop (91%) - 539 cp - IV(15-13-13)

The 88% Machop is also a July of 2016 one, which I believe is guaranteed lucky (I don't know much about lucky pokemon though).

I am at about 100 candies right now, so if I get a better one before I hit 125 candies, I'll definitely probably evolve that. However, out of these two, I am not sure which one I should go for. Both of them have 15 ATK, so I am not worried about that. So out of all my pokemon, this is likely to be one of my strongest immediately after evolving. I managed to catch entei for the month already. And I hatched a 96% Mr. Mime from a 7km egg today, which is also pretty strong. I do have other decent IVed pokemon, but machop is the one I have the most candies for right now. So considering it will be one of my first strongest pokemon, which one should I evolve?