I thought maybe the wrap weakend the metal by trapping the moisture and rotting it out, but it doesnt really look bad. I just tossed a 04 header pipe too
Therefore it will protect plastic and lower the heat buildup at the shock, even as a side effect. But yes, that is not why this ugly stuff is used, it is a side effect of performance. Heat will eventually will come out but at different places and at different rates. Your mufflers will run hotter for sure.Will it retain heat in the head pipe? Yup. Sure will.