Coil spring height

[fastbagged68]

Need some help.... I pulled the air bags off the rear of my suburban. When I did the air ride on it 15years ago I mounted the bags in the stock location but raised the top mount in the frame. My bags are always leaking out. I’m going to eventually build a new frame but in the meantime I’m going to install coil springs back into. I mounted a set of 67 el camino dropped coils that measure 11” uninstalled. Well that collapsed down to maybe 6”. My frame is almost on the ground. I’m going to buy some coils but need to know what the installed height is and what is the drop size. Any help would be appreciated!