One for the rich small block guys.

Disagree. The Chevy 632 is pretty new. Their badass crate motors were 572s, for a couple decades. And way overpriced compared to Blueprint for all that time.
I'm NOT saying that nobody built 632s till recently, only that the CHEVY 1000HP 632 is recent.
That's good, because we have a local machine shop that started doing them about 1995 or so. It did take a bit longer for the mainstream crate companies and GM to catch on.