[niles]

You do need them if you want your car to handle like a sports car and not lean excessively in hard turns.
Go to FFR forum search , they have a lot of good tech. discussions this subject.
Easy to do your self; get a Howe , speedway etc; suppliers that supply the stock car guys; can get all sort of bars with adustable mounts etc; relatively cheap probably about $100 an end.
I using 1.0 front and 3/4 rear

gn