Classic 1966 Ford Mustang
The 1966 model altered the trim levels on the Mustang. Also a new grille was introduced, side ornaments, wheel covers and even the gas cap. Automatic transmission became optional on the Hi-Po. New features for the car included a AM/eight track sound system and even one fo the first AM/FM car radios on the market. Round gauges and padded sun visors now became standard on all models.
Differences Between 1965 Ford Mustang and 1966 Ford Mustang
There’s a bunch of differences! Without going into painful details of all the options like wheels and trim differences, I’ll stick to just the main differences that are quickest way to tell a 65 from a 66:
The grill. A 1965 grill is honeycomb and the stock Mustang emblem in the grill has chrome extensions top to bottom and left to right:
The 1966 grill has a solo Mustang without the extensions:
The stock gas cap is different as well. In 1965 the stock gas cap looked like this:
In 1966, the stock gas cap looked like this:
In 1965, backup lights were an option so a stock rear view looked like this:
In 1966, reverse lights were stock:
In 1965, the Mustang had rear quarter trim that looked like this:
In 1966, it changed to this:
In 1965, the stock dash looked like this:
In 1966, the dash looked like this:
Without going into crazy detail, it was possible to have a dash like this in 1965 as well if you opted for the GT package (which also added a ton of other changes that would be a whole other conversation).
So, from the front, back, or side you should be able to tell a stock 1965 from a 1966 from the cues outlined above. Pics are sourced from various sources on the Internet.