I will need to put an exhaust on my 68 pretty soon. I live in an area where ther is a LOT! of Police around. I don`t want to get pulled over all of the time. any recommendations I have a 400 sb. I will be putting headers on but I don`t know which kind yet. Will I have to get catalitic converters? I have heard if you have an older car you don`t have to put them on,any truth to this.