Ok, this may be a dumb question. If I need a new VSS, how do I know which part number? I have looked online at Rock Auto, Advance And Auto Zone and when I put in '90 Camaro RS ( 305tbi with 700R4) each site shows me several different sensors ranging greatly in price and some refer to specific driven gear teeth. I thought I could just get the sensor first then jack the car up to change it. I shouldn't have to pull the sensor to take to the store should I?