Chuck, my 70 Fathom Blue L78 car has a dealer installed 290 4 bolt CE block. This car is an original L78 built 4th week of Feb. 1970. Dial chevrolet in Center Reach,NY(Long Island)did the replacement for the original owner in 1973. Don't know what else to say except these things are out there. I don't think you will find a 290 block that was factory installed as an L78.
wilma
