I am doing a transmission swap on a 91 geo metro but I am having trouble figuring out where the speed sensor goes. The transmissions looked the same but I am wondering if I have the wrong one. Can anyone help me?

The speed sensor is built into the instrument cluster, and runs off the speedo cable.

are there multiple types of automatic trannys for these cars? I hav ethe speed sensor off and it came off the tranny everywhere i look for references says it is on the instrument cluster but it came off the tranny I promise. other than this detail the tranny is the same would it hurt to just leave it off the car.

What you probably unplugged is the reverse light switch, or just the speedo cable. I'd like to see a picture of it, do you have a digital cam?