Jeff,
In looking at the photos the snorkels are different.
Photo 3 is the "short connector" version that jogs the inlet part of the snorkel backwards, 1,2, and 4 are the "long connector" that jogs it forwards. I was under the belief that the short/rearward is "correct" for a '68 Mustang and the longer was later truck/other use... as the short is harder to find (in my experience).
Is either type correct for a 68 Mustang? Plant specific, or ...