I in fact have heard of the search button and apparently google is pretty useful too, i've found a bunch of related info, but nothing quite helpful and im not gonna read them all so...
i recently bought a '95 240sx SE originally automatic that was swapped with an S13 SR20 motor and manual trans. the previous owner did not replace the sr20 manual speed sensor with an S14 KA manual speed sensor to give me a working speedo, he did however cut the plug off what i think is the stock KA wiring harness and the plug off the SR20 speed sensor in the trans. i have a couple other plugs within reach of the new speed sensor, but they dont match the new plug's setup. i also have (if i can remember correctly) a plain red wire with a red and white or yellow striped wire (that im guessing are the wires going to the speedo) right next to the new S14 KA manual speed sensor (green and black wires i believe).
the two exposed wires seem to be the ones i need, but if anyone knows something helpful before i break something else, id appreciate it.