A Silver Star is pretty much standard in Naval Aviation for a 'kill'. The VF-32 Gypsy's got DFCs in '89, as some thought they shouldn't have waxed the MIG-23s, or so the story goes... plus it wasn't a very pretty engagement.
Granted the last F-14 / NFO kills were Desert Storm
That means the 8 guys who shot down the 4 Libyans all got DFC's, I don't know what the crew that shot down the Mi-8 Hip in Desert Storm got but would be surprised it was a Silver Star. Which means the two Hornet pilots with kills in Desert Storm are the only ones so far that have gotten a Silver Star since the end of Vietnam for the Navy, so the 'standard' hasn't exactly been that the last 40 years.
In the past they have also given DFC for shootdowns of non-fighter type aircraft sometimes.
I can recall an instance in the Vietnam war were some F-4 shot down some AN-2 Colts in a relatively benign night overwater intercept and got DFCs instead of Silver Stars.
It was a mix for kills before the bombing halt in '68 whether one got a DFC or Silver Start just for a kill, only in '72 did it seem to become the standard for a kill you got a Silver Star.
For folks interested in aerial combat an excellent book on all the US aerial victories since the end of Vietnam, except the ones in the past few weeks, is
Debrief: A Complete History of U.S. Aerial Engagements - 1981 to the Present by Craig 'Quizmo' Brown, a former F-111 and F-15E driver. I had the privilege of actually meeting the author and got to talk about his book in person, it is excellent read.