I think the 2" is way too small. The muffler design has a lot to do with the flow capabilities too. The stock muffler is very restrictive. I'd recommend getting one the same size as the exhaust pipe or larger. You don't want your muffler being the bottleneck. If you want a quieter muffler, buy one that is as long as stock or longer. Longer means quieter and shorted means the opposite. Good luck.