I don't think they ever revealed that. I have the Ride/Handling springs in my GS. The PO installed them, and I remember him telling me he did so. There are no identifiers on the springs.
I have found the GSCA club springs vastly superior to the "off the shelf" springs referred to in the article that Larry references. Assuming the GSCA is the club to which you're referring? Decades ago I followed the article that Larry references above, for my '68, '69, and '70 GS'. They all floated afterwards, perhaps like the cars did originally, but too much for most of us now accustomed to modern cars and modern suspensions. I installed the GSCA springs in both my '68 and '69 GS, replacing the MOOG recommendations from the BPG article. In fairness to that article, it's many decades old. The GSCA springs cost me $$$$$ with shipping to Colorado. After installing them I ordered two more sets for my other cars. Again, these GSCA springs are vastly superior. The ride height is right on the money. The ride is soft, or perhaps not-too-firm, without any float. The first time I drove through an intersection quickly, trying to make it before the light turned red, I experienced no float as I sped through the high-crowned intersection. I saved the boxes that these GSCA springs came in, with "special order" written on them. But I'll defer to Jason who perhaps has found comparable MOOG lower cost alternatives?
I still have an unused pair I bought off someone back in the early 90's for a '71 350 w/air & they're in a Moog box.
I believe shocks simply dampen coil spring oscillations and have minimal effect on float. Please correct me if I'm wrong! I'm running KYB Gas A Just shocks, which come in two firmness ratings for our A bodies. I've tried both. Following the old article about springs, I purchased the recommended set for my '70 big block GS and they're too soft, even when paired with the stiffest KYB Gas A Just shocks.
“They are Duralast springs from AutoZone. I have used these many times and never had a problem Front FCS5398S Rear RCS5385S The are not "in-stock" items and will have To be ordered “ discontinued now it appears .
Those numbers are across the board for all brand of springs. Those numbers are available through Moog
