Vvt lock or not

MDS is Multi Displacement System. It disables four cylinders for an Economy Mode. I.E., better fuel mileage. When you delete it, it's all or nothing. Meaning you have to replace the MDS specific lifters and delete the MDS solenoids. There are plugs to replace the solenoids. Why aren't you using the heads off of that 2012? They are decent flowing heads. You should use 6.4 springs with the 6.4 cam.