I know this is a stretch but perhaps Bob Snyder, funnycar aficionado that he is, the guy who was there that day and took the photograph, by some slim chance, knows about or remembers the name(s) associated with the unlettered silver 1968 Hemi Dart with atypical dent in its quarter panel? I say it's worth a shot.
http://bobsnyderdragphotos.smugmug.c...1455&k=Mtd5F5n
M68