It's the later oddball MEL pattern.
"Later", so of the three bellhousing to block patterns for the M.E.L.'s, not the '58-'60; I'm guessing your saying yours is the really "oddball" '61-'65 second version; or the "later" or last '66-'68 version?
![Undecided :-\](http://fepower.net/simplemachinesforum/Smileys/default/undecided.gif)
Scott.