Then, when you get tired of screwing around with them, and watching the rust return someday, take them to a company that can do a good coating of ceramic (e.g. Jet Hot coating, but they're not the only one) both inside and out. Also known as high temperature coatings. Not only will they look better, they will last longer, lower temp in engine compartment, and give a marginal increase in power (not big enough to brag about, but there anyway). The more skilled companies have a choice of colors nowadays, beyond the traditional "silver".