Mega Metagross: VGC Competitve?

[DanielJames]

I want to make Mega Metagross viable on my team. I'm not exactly sure what the best build for VGC is though. Right now, I have an Adamant natured one with 252 Attack, 252 HP, and 4 in Defense while running Protect, Meteor Mash, Zen Headbutt, and Earthquake. I know I can get a more efficient build. The first threat I thought of was Mega Kangaskhan's Sucker Punch. What would be a good EV spread to live a Sucker Punch? Any other threats out there that are worth noting? Any help would be appreciated!