John Ames springs and a 12bolt?

I have noticed that the rear end of my car sits a little higher than the front with the John Ames Eibachs I have. I also noticed with 12bolts it raises the rear end of the car. I was wondering how bad my car will sit when I get a 12bolt. I think the car sits perfectly right now and don't want it to look like a drag car after I put the 12bolt under it. Is there a way to correct this or should I just get a different set of springs?
On a side note does anyone have the spring rates for the "John Ames" springs? Thanks