I really don't see FFDP/Rob Zombie coheadlining, doesn't seem like the two are strong enough to sell enough tickets. Korn did a lot of the ticket selling in 2010 when RZ was coheadlining, despite his resurgence in popularity I personally don't think he could be the top billed band. I'm personally expecting Avenged Sevenfold to headline with Rob Zombie as coheadliner with 5FDP or LOG in direct support.
4/22 - Alter Bridge/Monster Truck
5/16 - Mastodon/Gojira/Kvelertak