When running a stock hp setup, replacing the worn out bushings, body mounts, etc will do wonders to the ride. I had my front sway bar end links with worn out bushings and could not believe how loose the front end handling in turns felt. Similar to when the shocks are worn out. Some of the bushings had dried up and fell out. Once I replaced the end links with stiffer poly bushings the front end was so much tighter in sharp turns. Yes I know this sounds like Captain Obvious but I do not drive my car like it is in an autocross and only knew the bushings were gone when I heard something thumping under the car in turns which was the loose ends of the sway bar.
In the past I was told that if I planned to add some serious hp to beef up the frame. Stock frames were prone to twisting. The situation was similar to what was happening to late 80's Fox body Mustangs unibodies when high hp motors were twisting the frames and A pillars were bending and other body parts getting ripples from weak stock frames. I know this is like comparing apples and oranges but what was always drilled into my brain that the minute you modify the motor, do not neglect the frame or you will pay later on.