Solid cam questions.

You can run the Edelbrocks with the 9:1, but I wouldnt. If you are milling to remove the deck surface, you must also mill the intake flange, or the intake itself, to have things line up properly. Under .020" is not a problem. More than that removed, means bolt holes dont line up, and I always think ovalling the holes make syou look like a hack. You fix the bolt issue, but the ports also dont line up, and that costs power. So, now you're milling two surfaces per head, and you have the small chamber you need. But, now the pushrods are not going to fit properly, and you'll need to either order the corrrect ones, or shim the rocker shafts to get lifter preload correct. Your 284 cam has a lot of duration for its lift, but to be sure, you should take an afternoon and pull a head to check what you have now. This will only be a guide, but you'll be in the neighborhood for choosing another cam.