Speedometer correction (switching to 4.10s)

[-=Jeff=-]

Originally Posted by WVZR-1

Well - establish (for your car) either a rolling radius (center of rear axle to floor) or rolling circumference (chalk tire and floor 6 o'clock roll one complete rotation ,chalk the floor & measure). Is there a preference? Circumference I'd guess.

Then it's all math - if the OE (15) tooth is still in the car I don't believe you can do just a driven and "be happy"! Not having RR or RC a "WAG" with Marc's (13) would be a driven of 42 - 43. I believe you've got 42 now so just Marc's drive for a start.

Yes planning on Marc's gears.. well his drive at least

according to his site.. I need the 13/43 for the 4.10 (assuming stock tire size)

the 3.45 is a 15/42 so I will buy the 2 parts from Marc and install then compare to a GPS and see if I need to change anything. I am just trying to get all the parts in my possession before the actual swap..