I put a pair of 2 - 1/2 inch 24 inchers on my '59 Chevy Pickup (rrumbly 350) to replace a set of rusted out turbo mufflers. They sort of muted the sharp note of the open headers, but since I welded them to the header cones, and put a short turndown right out of the muffler, they were quite noisy; I could drive through a parking lot at just off idle and set off almost all of the car alarms in it. I put the truck in storage five years later, and they were so loud you had to shout to be heard around the truck.