Well jts, I would say that they were a bit higher in the front than the back. An inch or so. As far as raising yours at the back so that the car is level? or so that it is higher in the back? Either way, there's several avenues to take you there. You could do any one of the following,: In no particular order, ...Helper spring leafs, shackles with multiple positions, new springs and shocks, air shocks, taller tires in the rear, adjustable racing coil over shocks, air bag suspension kit. It really depends on what your going to use the car for, the depth of your checkbook, your mechanical skills and how you want the finished product to look and perform.
Assuming your just going to drive around town and such, and your car has the original worn out leafs and possibly shocks under it, if it were me I would invest in new springs and shocks first and see where that places the rear in relation to the front. If that's not enough then a little taller tire might do it.