[Dinsdale]

Interesting that your spring pads have 2 holes but I'm a Ford guy so know nothing about Mopar rear ends. What you are describing isn't unusual and I'm suprised Calvert didn't have an answer. I went through similar with my Mustang and ended up making a new spring pad hole.

The problem is a mono spring needs more arch to make the car sit as original. As you curve the spring you are also moving the housing forward. The Calvert springs use the back section to get ride height. It's also possible the centering pin is not in the same location relative to the front spring eye. It's tough to get an accurate measurement because the springs aren't flat but see if you can and compare the two. I know I had my housing in and out too may times trying to get the rear centered and the height I needed. If it fits well with the front spring pad holes I see no downside.