here's a good read on why the corvette uses leaf springs:
Corvette leaf springs - Ultimatecarpage.com forums

The big advantages are:

-It weights A LOT LESS than coil springs. One leaf replaces two coils. The two coil springs weigh 3 times as much as the one leaf. Additionally the leaf is placed at the bottom of the car. In addition to removing weight you lower the CG.

-It acts as an anti role bar. The article above explains how this works so I won’t. The advantage is you can run lighter anti-role bars because the springs are taking care of part of the job for you.

-The leaf springs never wear out. The vendor of these springs has never had to replace one due to fatigue failure. Coil springs to were out but you typically don’t notice on smaller, lighter cars. You do see it more on old, heavy Caddies and such. The improved fatigue life was really evident compared to the C3’s steel leaf spring. Thus this is an advantage over coils but not a big one.



What are the drawbacks for the Vette?

-They are expensive. We normally don’t think of leaves as the expensive suspension but in the case of the Corvette, coils would be cheaper. The Vette already has all the parts a coil sprung double A arm suspension would use. Pull the leaf off, replace the shock with a coil over and you’ve converted the Vette. Since the rest of the system is the same, the cost comes down to the price of 2 coils or one spring. Well if it was a steal leaf spring it might be cheaper (remember truck suspension is cheaper because the leaves also act as links).