Ultraflows can be fairly mellow at idle on milder motors without a lot of compression and especially without a lot of cam overlap. When you go big cubes, high compression and long duration they tend to get a bit louder.

I went with the Dynomax Hemi Mufflers because with big cubes, 12:1 and a big cam I felt the Ultraflows would be a "touch too much" for the neighborhood and town I live in. The Hemis are 3" all the way through and flow well, at least on par with the shorties. I believe the OEM style Hemi's are 2 1/2 to 2 1/4 ID, but I believe Accurate may make a 3" internal.

Here's a sound clip with 3" dmax Hemis:

http://www.youtube.com/watch?v=jd8GeXYYkKU&feature=channel_page