Hipo 273 66 4 speed cars with the 8.75 are not rare. Mid year in 65 ma Mopar decided to offer the 273/4speed cars with the 8.75. Too many of the 7.25 cars were coming in for warrenty work due to broken rear ends. Before the mid year change, if you broke the 7.25 it was replace by the 8.75. 273 2 barrel 4 speed cars didn't have that problem. Hipo 273 cars with autos came with the 7.25 as standard in 65 and 66 and had to be ordered in 66 inm order to get one. Here is rare. 1966 Dodge Dart GT, 273/4, 4 speed, 8.75, front power disk brakes, A/C, 14" wheels and tires. Guy in Oregon is the original owner of that very same car.