"THE BOOK DID NOT SHOW THE GT OPTIONS FOR 1965" The GT option was a mid '65 introduction.

This is the part of a group of options listed for 1966 mustang ,that refured to the GT model.GT equipment group,with high-performance v8 only includes ,dual exausts,fog lamps,special ornamentation,disc brakes,GT racing stripes [rocker panel mouldings deleted ]and handling package components [$152.20].limited slip differential [$41.60].rally-pac instrumentation,includes clock and tachometer[$69.30]special handling package,with 200 and 225 horsepower engines.includes increased rate front and rear springs,larger front and rear shocks.22-1 over-all steering ratio and larger diameter stabilizer bar [$30.64]. 14 inch styled steel wheels on v8s only. NOTE power steering and accent striping not available with GT equipment group. the source is the STANDARD CATALOG OF AMERICAN CARS 1946-1975. THIS WAS IN THE PERIOD OF TIME WHEN YOU COULD ORDER ALMOST ANYTHING ON A CAR AND THEY WOULD BUILD IT FOR YOU,YOUR WAY. THE BOOK DID NOT SHOW THE GT OPTIONS FOR 1965.