<VV> Ride Height

[Chris C, Warwick RI]

My wifes 63 Monza 900 pg is listing to one side.  Filled the tires to the 
same pressure.  And one side is 2 inches lower than the other.

What is the most likely problem.  Or can I only tell if I take stuff apart.

The shocks seem to bounce the correct amount.  No apparent oil leakage.

The shocks and springs are of unknown age.  I know we have not replaced 
them in the 6 years we have owned the vehicle.

Thanks to all.