It looks like a pretty nice 66 you found. The 4 barrel, disc brakes, and the HD suspension options are all real nice upgrades. According to the Galen book there were 1619 1966 Dart GT's built with the 273-4 barrel and automatic transmission. That includes hardtops and convertibles. There is no other breakdowns known for these cars. There were 2856 including the 4 speed cars. (1237) Like mentioned above, side marker lights and auxiliary lights in the grille added. Value? I have seen "asking price" on fully restored cars around $18,000 and a car like yours can be valued around $10,000 in good driving condition. The 4 speed cars bring a couple thousand more just because of their popularity. It's all up to you which direction you want to go.
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