Renowned Ford FE engine builder Blair Patrick says the "in the family" KR they have has it's original engine and A intake. This would be the first I've heard of. Blair is not known for hallucinating.
BTW the casting # is C8O"E" 9425-A in 1/2" tall letters stamped into a metal tag that was nailed to the wood casting pattern. The FoMoCo is in block letters between # 2 and 3 ports not the oval in back like the C intakes.