I am saying if you want to run those kinds of rpms you better do your home work. You are taking a already long stroke engine and making it a longer stroke and then wanting to rev it to the moon. And on top of that wanting to throw some boost on it.
And as far as the head goes. It is not going to flow at those high rpms. It will choke out and also you will have to go solid lifters because they will definitely not work. Valve springs most likely.
Look at the lift and duration on these motors. They are relatively mild lift. And not much can be done without dumping a lot of money into the head. Really around 10-10.5mm of lift is it before valve springs, lifter buckets, and the head has to be machined for clearance. etc etc. etc. After a drop in Camshaft is maxed out the next step is around 7-10k. I have talked to several machine shops and cam companies about all of this. YOu can also find flow data on the heads. I think some of it is posted on this forum.
Do not get me wrong I am not saying your power and rpm goals are impossible. Just I would go about it differently. Well maybe the combination is impossible. But I would use a short stroke 2.8 motor and boost that. I think that 600hp is probably around 20-30 psi of boost and your limiting factor is going to be getting the air through the head at high rpms.
You still have to have the crank modified and bearings and oil supply and control to spin those rpms. Electric water pump most likely. The list goes on.