Valiant, Duster, Dart, Demon (etc.) Transmissions
The most common transmission by far on the A-bodies sold in the US was the three-speed automatic A-904, with the column shift. Click here for Allpar's Chrysler transmission page.
Bill Watson wrote about manual transmissions for the Plymouth Valiant, Duster, Dodge Dart, etc.:
The 1960-1961 "A" body compacts had a 3-on-the-floor shifter, which was replaced for 1962 with a 3-on-the-tree. In 1964 you could get a 4-on-the-floor, even with the slant 6. That option continued with the 273/340/360 V-8s to the end in 1976.
Starting in 1970, Chrysler offered a 3-on-the-floor with the slant six on the Valiant. It was an all synchromesh unit, too. Near as I can tell, it was an option (except for the Duster 340), as it was an extra $14. The standard transmission was the 3-in-the-tree unit with synchromesh on 2nd and 3rd.
In 1970 the Dodge Swinger 340 had the 3-on-the-floor as standard equipment, with that transmission an option on all other Darts. For 1971 it was optional on all Darts except the Demon 340, which offered it as standard equipment.
In 1975 the 3-on-the-tree became an all-synchromesh unit. Starting in 1975, too, Chrysler offered a floor-shift 3-speed plus overdrive transmission on the Dart and Valiant.
In 1976, the 3-on-the-floor was a $28 option on Valiant and Dart, with the 3-plus-overdrive coming in at $127.
So, the 3-speed floor unit was an option, not standard equipment, with the exception of the 340/360 engined cars, from 1970 to 1976 on Darts and Valiants.
(All prices quoted in American dollars as available for the American market.)
Bill Greer wrote: The U.S. Valiant first sold in '59 as a 1960 model had two tranny options. the standard tranny was a floor-mounted 3-speed synchroshift. Optional was a 3-speed push-button automatic. (ref '60 Val Shop Manual).
Dodge and Plymouth have used four synchromesh manual trannys both 3 & 4-speed in 60s and early 70s models. different models had columb or floor shift. Automatics came push-button, column, or floor console shifter on various models. Mother Mopar didn't always supply a "standard" package and with all the rebuilding and rodding going on today, you may find almost any tranny in any model. (ref 64-71 Chiltons Repair Manual)