Formula S (HD) Leaf Springs

I don't know that those stamped numbers correspond to the part numbers, because those don't match anything in my reference. The following are all 6 leaf "HD" springs.

2808 607 - 1967 - HD except 383
2808 677 - 1967,68,69 - 383 (all)
3004 588 - 1968,69 - HD except 383
3420 183 - 70-72 - HD 2dr
3420 184 - 70-72 - HD 4dr
3549 945 - 1973 - HD
3722 293 - 1974 - HD 2dr
3722 294 - 1974 - HD 4dr