Has anyone done any research on the speedometer gears located at the transmition. I have a 86 K5 with 33 x 12.5 tires, 700R4, 3.42 gears. I am using a TPI with speed density system that uses the pulses from the speedometer gear. I know my speedometer is off-does anyone have any information for the correct gear to correct my speed? ANY HELP WOULD BE GREATLY APRECIATED.