It is the same as the SHELBY lettered version but predates it.
There are no date codes on those castings so you can't positively identify them but it is thought by some that the COBRA castings with the Shelby aftermarket engineering numbers like yours are from about 1967 and the SHELBY logs start appearing with the same engineering numbers in 1968.
It is a Shelby Autosport "aftermarket" item. Aftermarket in this instance simply meaning that it was never installed new on a Ford product before delivery to the first owner.
As an interesting note, the SHELBY lettered intake manifold on the 69-70 GT350's is a production manifold, sort of...it was installed by AO Smith, not Ford on the assembly line.