If you mill the head the pushrods are now too short by the amount that was removed from the head . I have no use for cast pistons . the same for cast rings . Cheap crap IMO.
I have already shaved the head
.030 and my stock pushrods have worked just fine. I've heard you can cut a bit off and still be okay. It'll depend on how much I cut off of course.
Edit:Oops, beat me to it lol. My cam will not be very radical if at all (Oregon Cam #2106 or #819, not sure yet ). Just upgrading small things to be a very nice driver/cruiser.