1963 to 1979 Corvette Leaf Springs

For the years 1963 through 1979 Chevrolet Corvette's 3 different 2 1/4 Inch wide rear leaf springs were used.

There was the standard duty 9 leaf spring, P/N ML357, in which the 6 longest leaves were curved and the 3 short one were straight.

In the spring business we call this a 6 and 3 or a 6/3 spring.

The Heavy Duty spring was a 7 leaf, P/N ML715.

There was also another 9 leaf spring, P/N ML813, which all the leaves were curved.

The difference between all 3 springs is the spring rate. (The amount of weight that is needed to deflect a spring one Inch is the down and dirty description of spring rate).

The spring rate for ML357 (the 6/3 spring) is 140 Lbs. for the 1st 6 leaves and 196 Lbs. for when all 9 leaves are touching.

The spring rate for ML715 (the 7 leaf spring) is 305 Lbs.

The spring rate for ML813 (the 9 leaf all curved leaf spring) is 196 Lbs.

All 3 springs are designed to have a slightly negitive arch, about 3/8 of an Inch, when they are at their designed load. The designed load for the ML357 and ML813 is 1,360 Lbs. and for the ML715 it is 1,325 Lbs.

In order for all 3 springs to be at the same height when under load, each spring has a different free arch.

The free arch of the ML357 is 8 11/16 Inches. The ML715 is 5 7/8 Inches. And the ML813 free arch is 7 1/2 Inches.

The correct way to measure the free arch is for the spring to be off the vehicle. Place a straight edge across the ends of the spring and measure down to the main plate next to the center bolt.

While we use the correct type of spring steel, SAE5160 High Alloy Spring Steel, the thickness's of the leaves have been adjusted to sizes the steel mills now produce. Way back when, the mills would produce quantities as low as 5 tons of a size. Today over 20 tons of a size is the bare minimum of a size they will produce. And that is a lot of Corvette springs.

While the overall thickness of the spring have slightly increased, less than 3/8 of an Inch, the fit, feel, function and performance of the springs are unchanged. The free arches have been lowered a bit from the factory specs in order to maintain stock ride height.

We do not paint our Corvette Leaf Springs so you can apply the finish of your choice.

Each spring includes full length liners between the leaves.

The end of the leaves are as close to OE as possible.

And each spring ships with clips banding the leaves together so they do not fan out during shipment. The clips are easily removed.

Go to our Corvette Page for other year 'Vettes. Or here for our 53 - 82 Corvette Application Guide.