my rear coil springs are 14" high, 7" wide, 5/8" diameter, and 7 coils.

The could be, but it's very hard to tell. Based on the measurements you gave and provided that they are nearly accurate, it looks like they are. If you are counting the very top and very bottom coil in your 7 coils then you have a spring with 119lbs spring, if you are not counting the top and bottom coil, then you're springs are 166lbs. Either of these numbers are spring rates that Chevrolet used.

Here is the link I used - http://www.proshocks.com/calcs/coilsprate.htm