I really don't know how u can get that high with this set...I'd like to share a set I'm currently 20th on the ladder with:
Eevee @ Eevium Z
EVs: 228 HP / 252 Def / 28 Spe
- Hyper Voice
- Last Resort
28 Spe helps you outspeed +Spe Nature 252 Spe Pikachu at +2. You go max Def to help you surviving Z Focus Punch or Volt Tackle from Adamant max Atk Pikachu. Hyper Voice was chosen to beat SubPunches Pikachu. You can go Stored Power cause you tank Focus Punches very easily at +2 but you're weaker against Volt Tackle ones. Yawn helps you beating Eevees.