Always change to a poly bushing while you have the chance. It's a great upgrade for the money, and you already have the bars off so its a piece of cake.
I forgot to explain, poly bushings are stiffer than the stock rubber bushing and the added leverage from the taller bars need these stiffer bushings to keep the bars from moving back and forth with the weight of your hands on the bars.
I thought that was what everyone would say I guess I was feeling lazy, but I agree I'm going to change to the poly bushings. Dr V-twins always got the stuff I love this forum....