What kind of power can be expected using S&S .570 cams in a 110" keeping the stock pistons and ported heads?
You'll need to get the compression up to a reasonable level for a S&S 570 (around 10:1). Milling the crap
out of the heads is not the way to accomplish that. Head milling is for fine tuning the CR, not for making
drastic changes. (There are allot of reasons why that's the case)
Put a dome in there to get it close to what you're wanting, then mill them a little (if needed) to bring it up
to where you want it. 5-6 CC domes are going to be needed.
If you mill too much off the head to get the squeeze right, you end up with valve to piston clearance and
intake manifold fit problems. Put pistons in it!