Hi badsix . . .
The guys from
Delta Cams can re-grind pretty much whatever you want in terms of a profile. But everything is a tradeoff when it comes to a camshaft. Duration is great at higher RPM but it takes away from low end grunt - which has to be replaced by something - increased displacement/compression-ratio or both. So it is good that you are looking at this from more than one dimension.
As for milling to get C/R - it has its limits. Bill Fisher's book suggests that older design head would tolerate as much as an 1/8" (0.125) of milling - yielding an increase in .75 C/R over stock (because of the reduction in combustion chamber size). Not sure if the later design heads will tolerate this much milling . . .
The big downside with excess milling is that it messes with the geometry in the valve train. The rocker posts have to be shimmed an equal amount - followed by the valve springs to get the correct uncompressed height. I also don't see how the stock intake valve recess/seats would survive this much milling - which means additional machining to create a new recess for the value and then grind a new seat. And I would be worried about head bolts bottoming out . . .
A pop-up piston seems a much easier route to added C/R . . .
regards,
stock49