Well, I stand corrected on the number of wiper switches in my Argosy. I took a few minutes to look closer at the wiper and washer switches on the dash and realized that I really do have two separate wiper on/off switches. One switch is a two position (low speed, high speed) and the other switch is also a two position (low speed, high speed) but can be pushed in to activate the washer pump.
The knobs don't look anything alike. To top it off under the left switch it says Wiper and under the right switch it says Washer
I don't believe the Argosy wiper motors are the coast to park style but I'm not certain of that. When comparing the Argosy wiper motor to the 345 wiper motor the wiring is somewhat different. See attached pictures.
My plan is to scrap the two Argosy wiper motors and install the 345 units. I also will use the same wiper control switch that Dan used. I am a little bummed about the wiper switch. The price went up $13 from the time Dan posted the link to when I checked it again today