they do make a difference, with the rubber in each side can flex inside the rubber another 1/2" or more which means that much more air under the outside side. Not to mention the new bolts are like 3/8" as opposed to 1/4". Never skimp on suspension stuff imo. If you have the money/skillz/patience you should get the whole urethane kit, it makes a huge difference. go outside and kick your rear wheel and see how much it moves. it's scary. lots of rubber in there.