Wiper speed?

I currently own a 73 swinger w/ 3 spd. Owned a 71 duster w/ 3 spd. , and 69 RoadRunner all with original 3 spd. So, not sure when the start date was for them but certainly went back before 74.
The road runner was air grabber. Im not sure but I think the 2spd motor will hit the larger air cleaners on them. I have heard that about the shakers.