JSALLEN, if all you are after is more volume, then yes, a muffler like you are talking about will accomplish that. now, if you are looking at getting more power out of the truck, this is a loaded question. What do I mean by this? It is easy. You can open up the exhaust and get something that will make a lot more power from the engine, but this is due to reducing back pressure. Back pressure is what makes the low end torque (what makes the truck get off the line from just above idle). So, a large diameter exhaust system will be great for the moments when you are at 5,000 RPM. But down at 2,000 RPM, it can be a real drag because the engine will not be able to make adequate power. So, there in itself becomes a balancing game of opening up the exhaust system to get more power, but keeping it restrictive enough to make good low end power and keep the mileage up.