I am not sure why they call it a clone and replica. It appears to be a real motor from 1969 (at least the block) assembled with original parts (some NOS). It has no VIN stamp so maybe sold over the counter?
If it had a VIN on it, it would have brought more money. Then again, it probably would of had a clone car built around the engine!
Wasn't there a case a while back where there where 2 ZL1's with the same VIN claiming to both be original? One wit the original body and the other the original motor?