HK 3's
I have the HK 3's and love them on my Black Retro. I ordered my set after the heat shield retrofit so they had the heatshields welded in place. I have not experienced the melting of the cover. But I think you run that risk if you don't rejet because they will run hotter if the bike isn't jetted properly. Some here will disagree, they will tell you that you don't need to rejet if you add only the pipes. I will tell you that if you add a K&N filter and rejet with the pipes you will like the performance boost. I have since added the Baron's Big Air Kit and this thing is a ROCKET!