The guy I baught my car from said the speedometer gear broke, and he gave me a new gear, which i have. He said it goes in the side of the transmission, but I have no idea where to look, could you guys give me an idea of where to look, and do you think it could be swapped without jacking up the car, It's stock height.

 

Have to jack it up. It's on the drivers side of the transmission towards the back. The retainer is held on with one bolt and there will either be a cable or a wire plug in the center of it.
Don't get it mixed up with the governor cover.
Remove the bolt and retainer. wiggle the speedometer gear housing out, then just pull the gear off and replace it. This is assuming it is either a mechanical speedo or electronic with a gear type sender. Not the type with a reluctor and tone ring.