L72 block

[Mr70]

EARLY assembled~(block used until Jan.1968)~Passenger & Corvettes used these blocks.It came in either 2 or 4 bolt main caps.
Are you looking for something dated for your vehicle?..if so
the casting date is located above the starter mount next to the freeze plug.

Before this block,the 1967 427's used #3904351 as a 2 bolt for the 427/385HP Passenger cars & Corvette 427's used the 2 & 4 bolt.
After your block,the later 1968 427's used #3935439 available as a 2 bolt-390HP & 4 bolt-425HP for Passenger applications.This block I think was used for the early assembled 1969 427 Passenger & Corvettes as well..