Thanks guys. That is some helpful info! Just to clarify in my head, a 6.4 cam, get some 6.4 springs and it's good to go?

I don't need the $90 lock out for the VVT to put in a 6.4 cam? I think I will leave the MDS alone too unless someone else has a good reason for taking the heads off to delete it.

I'm going to get a Holley HP system to run the fuel injection/ignition so I will tune it with that.