The JGC coils I have measure .58 coil thickness, nine coils tall, approximately 16.5-17.5" tall. I have no way to tell why, but the coil springs I've seen from different JGC's have had varied coil thicknesses, but they ALL have 9 coils. That's a good way to tell which coils you have. Cherokee coils only have eight coils.
The interesting thing to think about is: stock Pathy coils have a spring rate of about 150 pound-inches. Going up in coil wire diameter, even in only tenths of an inch, drastically increases the spring rate. A Pathy spring made with .52 wire would be about 175 lb-in, .54 is 205, .56 is 240, and .58 is 275.