Leaf springs and shackle problem

Hello ,
I purchased a set of like new leaf springs from a 68 Dart, and installed them on my 74 Duster. I am wondering if I somehow mixed up the front mounts, because the springs seem short for the car. The rear spring eyelet is in front of the rear frame mount, in other words the shackle sits at the same angle as the spring in the air. When you lower the car onto the ground the spring pushes the shackle into the trunk floor.. My car had a 7 1/4 rear, I installed an 8 1/4 with the new springs, and the 8 1/4 shock plates and used the shackles from the 7 1/4 set up.
Thanks,
Chris