Ok I have a chevorlet 350 motor, Edlebrach carborator, Edelbrach intake, vortech heads, and I will probally get hedman headers. I want the best mix of sound and performance without crackles and obnoxiously loud sound. Kinda a tuned exaust sound. I wanna know what to tel the exaust shop when I take it to them. I have some used flowmaster mufflers I could use or would it be a better idea to get new ones or a different brand?