Finally got a chance to try to determine my rear-end ratio (1984 GMC pickup truck with stock rear end sofar) so followed the steps whereby I jacked up the truck and marked the driveshaft and tire then spun the tire one circle to determine the number of revolutions the driveshaft makes.
And; I get 1 and 1/3 turns out of the driveshaft for one wheel rotation. Just to be sure I spun the driveshaft by hand one rotation and the tire went 3/4 of a turn.
I was expecting something like 2.73's (as per data sheets for that year) but 1.3??
Am I doing something wrong or is that possible. The instructions don't say anything about doubling the number you come up with (which would then make more sense)