rear shock on Dart to short? (large pic)

Months ago I swaped the worn rear shocks (Hi Jacker from the former owner) with a pair gas shocks I got from a friend. His car is a 69 Coronet but I dont know if he used them on his car. Now (!) a guy ( :) ) asked why the car is so flat on the back. Is it possible that the shocks are simply to short? I changed them without any measurements and the leaf springs seems to be ok (very stiff). And if its so - what can I do?




Michael