I had been looking into options for the wipers for a while. They make kits but I didn't really want to spend that much. Also, I wanted to use the GM wiper switch on the column. All the conversations say they won't work with the GM switch. I took it as a personal challenge.
This is the motor I used.
Wexco 4R Wiper Motor-4R2.12.R110D...
https://www.amazon.com/dp/B00G1G1FXI...p_mob_ap_share
It's a semi universal 2 speed self parking motor that looks identical to what all the conversion kits come with. I used a piece of 3/4" tubing welded to some 1/8"x1 inch strap but you could use angle iron also. The rubber grommets are optional, none of the kits I saw came with them but I wanted to try and help keep noise down. I still need to make a small bracket to hold the other end of the motor steady but that's an easy one.
I bought a 1/2" collar from Menards for about $2.50. It measures .505 inside. The splines on the motor are about. 550. Ran a 17/32" drill bit through it and then took a small triangle file and cut splines on the side opposite of the set screw. After that I took a Dremel and a grinding Stone and opened the rest up until it was just big enough to for over the splines of the motor.
I reused the wiper arm of the original vacuum motor. Just ground the end of the shaft where it was staked and then pulled it off. Centered it on the collar and welded it on.
That's really about it too mounting the motor. It can point down and hang between the column brace and cowl vent bracket or point to the left above the column brace. Still clears the defroster ducts and the cowl vent linkage.
Just watch when you make the mount. Try and keep the wiper arm the same distance from the mounting holes as the original motor and the same height when you look from the end. That should help keep the wiper linkage from hitting stuff.
The wiring wasn't that bad to get worked out. The factory GM system uses constant power and switches the ground for high and low speed. The conversion motors are grounded all the time and switch the power between the park circuit, low speed and high. Wiring them backwards isn't a good option. Tends to let the smoke out.
For the two speed GM switch without delay there is three wires going to the motor. Low speed, high speed and park. You need power to one of the three. There might be a fourth wire if it doesn't ground through the case.
What I did was use two 5 pin relays and use the ground signal from the GM switch to control them. One relay switches between low and park. The other relay switches between high and the first relay. Hopefully the diagram makes sense.