I'm trying to find out my rear end gear without pulling the cover off. Isn't there a calculation you can do based on the number of turns the driveshaft does in relation to wheel turns ?

For a non-posi:
With transmission in neutral, Jack up only one rear wheel and spin it around exactly two times. Count the number of driveshaft revolutions.

For a posi rear:
Jack up both rear wheels and spin around one time. Count driveshaft revolutions.

Be sure to use jackstands.

A little over 3 driveshaft revolutions would be a 3.08. About 2 3/4 revolutions would be a 2.73 etc.

Mark