Does anyone know what gear we need to change to, it has the white gear currently and I thought it said 2.79 on our rear but have since read that the 73 came with the 3.00 gears only, regardless we are running 4:11's now what gear will make speedo show correct, best we can tell from pacing the car is speedo shows about 10-11 mph over actual speed being driven
All depends on what the output shaft tooth count is... Each tooth added to the driven gear will subtract approx 2.5-3MPH, if you have a 17 now go with a 21 as it's the largest tooth count Ford sells... There is a aftermarket 23 tooth but umless you have a 19, will probably be a bit much for 4.11 gears... There's a calculator on the Ford Racing site, but again need trans tooth count plus height of tires...
ok well ours was 2.79 then, went to 4:11's, rear tire is currently255/70R15 but that will be changing and will probably not be as tall since we are going wider