i'm not an expert by any means but I'm a little confused by your post. You said if the rearend were on the springs they would flatten out? In my mind that says the spring are arched up. Maybe I am not understanding...(which happens a lot to me
I have kind of similar problem with my truck only with the stock springs. I removed every other leaf and am putting a Nova rearend in. But in moving the position of the rearend towards the back of the truck which is needed to keep the tires centered in the wheel opening, the axle doesn't sit in the low part of the springs and is about 2 inches or more rearward of the center of the leaves. Just wondering if this is okay.