If you want to say Hemi dart/Cuda, then ya, it's a toss-up on whether you can consider them 'Factory Built'.
But the 1965 A990 Hemi Coronets and Belvederes came down the assembly line, and produced 11.09/125mph.
Read more about them here:
1965 A990's Bevedere and Coronet
Any Hemi car that was not equipped with the Factory Crossram race hemi cannot be considered a contender. The inline dual quad motored cars were a much milder version (street hemi) than it's previous cars.