Yes, the 1:1 is by far the most common Mopar 4 speed. Buuut, as 67Dart273 sez, you can possibly find an overdrive 4 speed. Some of these were used in the slant 6 Feather Dusters and Dart Lites in '76 (and maybe '75?). I owned a Dart Lite and ran it to about 250k miles; it really and truly would get about 28-29 mpg on the interstate. But part of that good mileage was a very low rear axle ratio. (2.76 or 3.0 I think....) I recall these looked different than the 4spd OD pictured but certianly can't swear to that anymore. (But the AL box looks right...)