last 2 digits in the pinion # is the # of teeth. Jack 1 wheel off the ground/trans in neutral/stem at 12 O'clock/rotate tire 1 revolution/count # of shaft turns/divide by 2. 2.76 is 2&3/4 turns/3.23 is 3&1/4 turns/3.55 is 3&1/2 turns. measure height with tire at correct psi. jack it up high on the drivers side to minimize fluid loss. A GPS would be nice as you could get the exact % of error & that is the % of teeth change you need (less teeth in your case to speed it up) tho that would mean pulling it to check the teeth # then sourcing the correct tooth pinion then jacking it up again & pulling it again (a mess) where as going by the chart would entail doing it only once tho the chart might be slightly off but I used it & it came out dead on. If I had to choose between 2 close teeth selections I would the speedo to read a hair high (could prevent a ticket)
