You need the 70-71 switch to fit your wiring harness not the 72-74 switch. The wiper motor can be sourced from any year of car if you’re not wanting correct numbers. The 077 motor is more pricy. You have to get an ebody crank to fit the correct year model of motor. The arm is different as well. I just sold a complete restored setup to a customer for his 70 Cuda. I used two guys on the board here for work and parts that I did not have. I think the total bill was a little over $1000. It was a 73 motor and crank with a converted variable switch. It was a c body switch converted over to fit an ebody. Finding a 380 switch is more expensive and you can’t read the part number once installed anyway. NS1AAR and Devinism can help you out.
Not 100% correct. The wiring is the same for any 3 speed harness.
It's the plastic spade ends that can be changed to use either switch.
The later year just used a single plastic holder.
