73 duster slant 3 on floor ?

I don't know anything about dusters & beyond, but my 61 valiant had a 225 slant with a 3 on the floor, what a blast to brive. I heard at the time this combo was rare, that 225's had auto, & the 170 were manual,don't know how true that was. All I know 2nd gear scratch was easy to get.