I blew up the tranny in my RS a while ago and have been looking for a cheap replacement. I am having a hard time finding a rs tranny for a reasonable price. I have a 1995 legacy that just blew the headgaskets and I was thinking about swapping the tranny and diff from the legacy into my RS. All the sensors look the same except the speed sensor. On the RS it has three wires and on the legacy it only has two. Does anyone know about how I could make this work? They look like two completely different sensors so I don't know if I could just swap them.
You can just swap them. I'm surprised your 95 has an electronic speed sensor, I figured it was still cable at that point. Anyway, I swapped a 97 outback trans into my 2002 RS and same deal: car needs a 3-wire, trans had 2-wire. Swapping in a 3-wire sensor will work fine and is the easiest option. Mine reads high I think because of incorrect voltage(EDIT: this is not the case, my input voltage is correct), but final drive may play a role. Any 3 wire sensor will do but I recommend one that matches your gears.
Or you could find a 2G legacy cluster and use it's onboard computer to translate the signal to something the rest of the car can use!