Help: how to make impala ride like lasabre?

03, 3800, looking to find out what is the diff between the impala and the buick lasabre ride that make the impala less "ship feeling' than the buick. Any suggestions?

Tires, stabilizer bars, spring rate, shock/strut damping rates.

Tires, stabilizer bars, spring rate, shock/strut damping rates.
which one makes the most diferrence?

Tires and springs make the most difference. The Impala rides on a shorter wheelbase as well, making the ride choppier.

Other than being a Buick the major difference in suspension is both the LeSabre Custom and Limited models have the electronic rear self-leveling air shocks.