Your post jogged my memory, I've had this set of new, reproduction cast iron small block headers in a box in my garage for 20 some years. They are the hi-po set, C5ZZ-9430-B and C30Z-9431-B. They are new, never installed, some surface rust which wiped away with an oiled rag. I paid $325 then, will sell for $250 plus shipping.
Alan Sorkey
Shreveport, LA