Looks like this PN only shows up from one vendor, but this is a 310 lb/in front spring, and looks like stock PN on my 98 SS 'vert. It is NOT 1LE, which have a spring rate of 360 lb/in.

I had to do a good bit of looking, thanks to the retarded PO, who wrecked the right front suspension, and then had it put back together with the wrong parts. Whatever they used for the repair, made the right front about 1" lower than the left front.

Fortunately, my buddy's shop was cleaning out a bunch of junk, so I was able to find a matching PN on one of the batch of stuff he had, and can now replace the one incorrect spring on the car.