This is getting, as Alice in Wonderland would say, "curiouser and curiouser". I am at a complete loss, now, and need some clear understanding of what is going on with these leaf springs my son Aaron bought for his '74 Duster.

The car's stock springs have five leaves, 2" front eyes (with bushings for 5/8" bolts), and 7/8" rear eyes (with bushings for 1/2" shackle bolts). The springs sold to Aaron as "super stock" are the exact same length, have only four leaves, but have the exact same arch when laid on top of the stock springs, have smaller 1-1/2" front eyes (with bushings for 1/2" bolts), and the same 7/8" rear eyes (with bushings for 1/2" shackle bolts).

"OEM (5 leaves)" vs. "SUPER STOCK (4 leaves)" - Same thickness



"SUPER STOCK (top)" vs. "OEM (bottom)" - Leaf number and arrangement is different



REAR EYES FOR SHACKLES and FRONT MAIN EYES



I purchased a 5.2104 bushing kit on the recommendation of Energy Suspension's technical support, for "440, 426, and super stock" applications. The kit has 1-1/2" front eye bushings with 5/8" bolt sleeves (yeah!). However, the rear shackle bushings are larger 1" (not 7/8") and have 1/2" shackle bolt holes. Close, but no cigar.

I'm guessing I can probably work out the bushing issue, but what doesn't add up and is confusing the situation is the similarities between the two sets of springs. I suppose I first need to better understand what exactly "super stock" springs are. I had thought they would be "beefier" with either more arch, more leaves, or thicker leaves to give a stiffer ride. I was told that a set of true "super stock" springs would leave the car a bit higher on the right side because of the extra leaf to resist the torque of a hard launch.

Would some of you who have a good handle on "super stock" springs please explain what we have and is there really any advantage to using them? By the way, I have not been able to find any numbers stamped into either set of springs, so that is not going to help.

Thanks for any help,
Jerry

simple answer without a long drawn out explanation... metal thickness is only one factor to comes into play with spring steel. how the metal is work hardened and annealed can give different spring rates for identical metal thicknesses.

You're absolutely right, Jerry, but what I hoped to learn is whether this set of springs is what is commonly referred to as "super stock". I was merely showing that the thickness of the four leaves is 1", hoping someone with SS springs can use this measurement as a comparison.

Jerry

my 3400lb SS springs hav a couple of half lenghts in the front segment. I believe the 2800s that I had did so..

In any case, the one photo that shows the short segment leaf next to the axel is wrong, the short segment should go on the bottom, eh?

A-body super stock spring P/N P3412002 and '003 have 0.290" thick main leafs and also should have the part number somewhere on the bottom of the spring.

please explain what we have and is there really any advantage to using them? By the way, I have not been able to find any numbers stamped into either set of springs, so that is not going to help.

Without any numbers,there's no way to tell what they are.
They look like stock A body springs to me.