Yes, from what I understand they did. My 66 Dart had the HD suspension option. It had 6 leaf springs originally. I ordered them from ESPO over the winter when the car was locked up in storage. The gal asked whether it had 5 or 6 leaf. I said 5 and got a stock spring pack (no 1 or 2" over). Although the springs have settled and I added tall 15" tires I think it sets just right for the look I want.