For some reason that's how it came from the factory. The front was 1.3" higher than the rear, but you can level it out and still be within tolerances.
------------------------------------------------------------------------
http://californiaspecial.com/forums/showthread.php?t=6889
Ford specs for ride height
Here are the Ford specs for ride height.
Ride heights are measured from the ground to the highest most point of the wheel well opening (which should be though the center of the wheel).
For Mustang with standard suspension:
Front - 26.68 tolerance +1.00 and -0.70
Rear - 25.39 tolerance +1.00 and -0.75
For Mustang with GT and Special Handling Package:
Front - 26.49 tolerance +1.00 and -0.70
Rear - 25.49 tolerance +1.00 and -0.75
All dimensions are for Mustang with:
Full tank of fuel
All engine fluids at full
Spare tire with wheel in design position
Front seat at rearmost position
Jack and components in design position
Tires inflated to 24-psi front and rear (for ride height evaluations only)
6.95-14 tires
Adjustments for other tires:
E70-14 subtract 0.10
7.35 x 14 add 0.20
F70-14 add 0.30
FR70-14 same as 6.95-14
All dimensions in inches