CB500 four HEADER??

Does anyone know where i can get a header for a CB500, im not sure what year 73?,74? i havnt gotten it yet, my uncle is giving it to me may 28th,it has 3,000 miles on it was only used for about 2 years and my uncles friend died in a motorcycle accident so it scared my uncle away from riding so its practically brand new, although im sure carbs and tank will need to be cleaned, but its been in a garage so hopefully its not that bad, it will be my third bike and im 16, so i dont have much money but i still would just like to know where i could get one in the rare even that i had money to buy one