Variables such as the vehicle’s axle ratio and tire diameter affect the accuracy of the speedometer. The following speedometer drive gears and driven gears are available for the 700R4 / 4L60 transmissions. Most cars and trucks with low rear end ratios will take a 15 tooth drive gear. Nov 03, 2015 · How to tell what gear ratio is in your car without taking anything apart!! Calculating gear ratio on a chevy mopar ford by turning the rear wheels and counting how many times the pinion gear turns ... This is the Diff Ratio Guide. It represents our differential and gearbox repair experience since 1968 and is also a partial record of most of the vehicle types we have ever worked on (some information has been omitted for commercial reasons). This is a working document we use everyday as a reference and to which we add information periodically. Apr 19, 2017 · Hot Rods Gear ratios and diff ratios ... Currently has a Holden 253, four speed and 2.78 gears. ... should also check sites that have calculators to help figure most ... But to answer your question. There only one original and stock diff centre for all FEs and FCs, which has a 3.889 ratio. Having said that, other Holden centres bolt straight in, including 3.55, 3.36, 3.08 and 2.78. Anything shorter than 3.36 is going to put a lot of strain on first gear when you take off. 3.55 is a nice cruising diff. Does anyone know what diff ratio was standard in an HJ ute with a 253/trimatic. I've currently got a 3.08:1 and it's great on the highway but want to give it a bit more oomph! What ratio would you all suggest. I don't want it revving it's t*ts off but something a bit lower would be better. 4.11 is definately out of the equation.