First things first. If you mill the head that far, you'll kill flow. Hard. Don't mill the head that far for that reason all by itself. It's a bad deal.
Second, if you are worried about quench, you can fix that by sticking the piston out of the deck. This is the preferred method and the method Chrylser calls out. You can have quench with that head and not kill flow. BTW, if you mill that head that far, not only does it kill flow, it actually makes reverse flow go way, way up. That's a big power killer.
Third, and I'll say this until my teeth wear out, quench is a band aid for a crap spark plug location/chamber and emissions just as much as it is anything else. I've typed out a long, LONG post on this. As an example, a Hemi uses very little total timing, is about as detonation resistant as anything and yet has virtually zero quench. You can give the Hemi some SQUISH but not quench. And yet and still, you have to work hard to drive a Hemi into detonation.
Same thing with a small block dodge. Or the W2. Usually 35 total, damn hard to drive it into detonation unless you are just wreckless or stupid (not saying you as in YOU, saying you as a general term).
That head will feed bigger inches if it's done correctly. If not a W2 head, what other options do you have?
When you are doing that many inches, you need to make sure you consider the details. Because you will be induction limited, every little detail like reverse flow, throat area, valve shape, cross section and the valve job become critical. Big displacement, induction limited engines explore flaws because the actual air speed is much higher because the air demand is much greater.
You've also given up a HUGE amount of Rod ratio, and regardless of all the bull crap David Reher and some other engine builders love to publish Rod ratio matters, especially in induction limited applications. Even Chrysler admits this. When you are David Reher and most everything you build is NOT induction limited, then Rod ratio isn't that important.
Whatever intake manifold you use, I highly doubt you'll get by without at least some welding. You won't have enough area to feed that many inches, unless you have an operating range of a diesel. I weld on a Strip Dominator for 340 inches. Not because I love TIG welding so much, but because you can't get the shape and size you'll need without it.
I hope this helps. To do what you want and do it correctly, it will be likely you'll need a custom piston. You'll have to fight the piston guys because they just don't get that a positive deck isn't a bad thing, or criminally wrong. To keep the CR where you want or need it, and get some quench if you want it you'll probably need a piston with a positive deck and a reverse come on it.
