I replaced the vacuum wiper motor back in the early 70's with the single speed wiper motor and linkage from the '63 parts car that I got the drivetrain from. Back in the mid-90's I bought a set of the Argentina repro wiper arms that suppose to fit the Falcon. I found out the hard way the spline count was different than the pivot on the linkage and it broke the ends of the wiper linkage while installing the arm. Also they don't have a stainless steel cover to hide the spring. While getting another wiper linkage off a '64 Falcon at the junkyard I also got a wiper motor and switch out of a '76 F-150 that came equipped with intermittent wipers. It looks almost the same as the 1-speed motor but it has the wiring harness made into the motor. The signal speed motor has the wires have a disconnect plug on the motor, also the bell crank was a different length. I used the Falcon bell crank on the truck motor. I cut the shaft on the 2-speed switch the same length to match the old 1-speed switch after it was installed leaving enough length for the washer pump to work. Adding delay wipers was granted by adding the control box between the motor and switch.
A trial fit reveals interference with a brace behind the gauge cluster using the larger intermittent switch. I took a angle grinder and flap wheel and made a flat spot on the switch to get it to fit. Take your time and use caution grinding the switch because the inside of switch will get hot while the outside stays cool.
Update- Junkyard wiper motor was on its last leg (weak), I bought a new motor from auto parts store. The rebuilt motor comes with ends on the wires but no plug. I used my plug after carefully removing the old wires from the plug by releasing the retaining clip on the spade connector with a very small Allen wrench. Click Here for a short video of the wipers doing their thing.