Hi Delta,
Thanks for your updates, I will check out these links. Honda4fun I know well and I know the Italians produces some mufflers. I will browse and see what to find. I also hope that a 4-2 overrules any need for rejetting. I have 2 new 4-4 sets, but I have 3 bikes. One set will go for my CB 550 keeper, one for a CB 550 Police and If I go cafe on the last one, that would help me out.