not too noisy
I had to go through the same deal. I finally found some nice quiet ,with a bit of a rumble. I believe they are Walker quite flow. I may still have the boxes out in the garage. If so I'll verify that, and send pics. Got at O'Reilly's had to order but had them the next day.
Basically the same as the Flowmaster, just a little longer, at 16inches on the Walkers