Ball and trunnion 4 spd

If it came out of a six-cylinder A-body, it's got a deeper first gear (3.09) than the V8 and B-body transmissions (2.66). The other three gears are the same ratios and it's every bit as strong. That low first gear allows for a decent launch with taller axle gears like 2.76, 2.94, or 3.23. The Slant Six gearset is easily identified by a semicircular groove cut around the input shaft just forward of the clutch splines. It was used from 1964-'66 and only in A-bodies to my knowledge, although I have a '67 A-body transmission with it as well. Early production? Swapped years ago? I don't know.

Fun fact: If you have a damaged close-ratio 3.09 input shaft, it's exactly the same as the one used in the aluminum-case overdrive A833 in terms of functionality. The aluminum A833OD input does not have that groove, though. Neither does the input from an iron-case overdrive, but that one will not work. The iron-case overdrives (1975-'77) used a high-helix gearset, so the gear teeth will not mesh correctly. The high-helix OD gearset was the quietest A833 gearset made. Unfortunately, it was also the weakest.

I have the close-ratio 3.09 gearset in my '69 Valiant. In a '68 case. With an A833OD input shaft. It's a mutt, like the rest of the car. :D