Those are the correct numbers. They're not necessarily tied directly to a year the block was cast, but more to a 'run' or series of the block. Ford casts tens of thousands at a time, sets them out to season, then machines and uses them. So it's possible to have an E9 block cast in say 88 for the 89 model year and the same run of block could still be in use until 91... 92.. etc etc. The castings HAVE to season for an extended period of time before use or they buckle and warp when heat cycled. The old 351M/400's in the late 70's were horrible on main bearings and bore centers 'cause they were rushed into serive without being seasoned properly. And if they needed more block, but weren't updating anything, it wasn't uncommon for another run of the same block to be made years later. Say more E9 blocks being cast in 92 (which TECHNICALLY would be F2), but since no changes were made, the same E9xx casting would be used. Sometimes they added suffixes to the castings on the later pieces. Like say instead of E9SE on the first run blocks, it would be E9SE-AB on the second run.
Hope that makes sense.
Steve