I have seen air shocks on 2 firebirds and in each
case the car had a broken leaf spring.

The air shocks worked well at balancing out
the rear suspension. If you need to raise or
lower rear end for what ever reason these
shocks will do it.

However, you effect the handling of the car.
The ride will be stiffer and you will have less
travel on your shock absorbers. The farther you go
up with the air shock the less travel for
shock absorption.

Personally, I would only use air shocks
if my rear suspension has been weaked or
I have an increased load affecting my ride
height.