Did you have only one wheel jacked up? If so, the spider gears in the differential change the apparent ratio. The only accurate way to check it is to roll the vehicle in a straight line with both tires on the ground and count the turns of the driveshaft. I'll bet you get nearly 4 turns of the driveshaft to one turn of the wheels unless the rear end has been modified. You'll need an overdrive trans like a 700R4 to get the RPM down to a manageable level, or put in a 3.55:1 gearset.
Jerry
Last edited by Hotrod Lincoln; 08/05/2011 3:14 AM.
