FWIW, when I was putting together the specs for my build seven or so years ago, I made a half-ass search for a nice, unmolested 427SO block, and was not happy with the results (original Ford, not the newer castings). The result was that I went with a very nice 428 block. In my own personal opinion, there's no difference to me between a newer, after-market iron 427SO and an original 428 block. In fact, I would
rather have the original block. Nice 428s are getting harder and harder to find, btw. Of course, I would rather have a newer after-market block over any crappy original block.
Soooo, what that boils down to, IMO, is that a nice, original 427SO block is the best of all worlds, but a nice, original 428 block is more desirable than the newer after-market blocks (and let's just forget the aluminum versus iron thing). Others will no doubt disagree, but that's how I see it....
