I used the Welded Ultraflow #17513 on my 71 Roadrunner with a 383 engine. No drone, nice tone. Also see chart below and note that at 2200 RPMs the Flowmasters are pretty loud 92-93 decibels. Ron

What is also interesting about my chart(s) is the amount of air the mufflers can pass. One might argue mufflers do not work strictly with air but we saw a definite relationship in air flow/track performance (as do manufacturers when they look at exhaust back pressure versus power output).
Tom Hand

I have the large (20" long case) Dynomax SuperTurbo mufflers and they do a decent job of reducing exhaust noise and did not seem to hurt performance.
I have the 3" in/out mufflers that came with my TTI exhaust kit on the 500" stroker (near 700 HP?). With the 3" size and big engine the exhaust is still fairly loud.
I also had the 2.5" versions on my 360 RV engine (330HP?) and they were fairly quiet till you got on it.
The Super turbo mufflers do as stated, pretty quiet without much if any performance change, but they don't have a really nice sound/tone in my opinion.
I have heard the Hooker Aerochamber mufflers on a friends car, and I really don't like how they sound either. I don't know any Magnaflow muffler cars for comparison, only my diesel truck with 5" exhaust
I have a chambered IMCO muffler on a 318 that sounds nice, but not much power flowing through it either?

dynomax 17748/49--large body turbo muffler, or the largest case magnaflow you can fit.

Thanks for all the help. I ordered a pair of Dynomax Super Turbo's today.

magnaflow

Looking at that chart up a few posts I am shocked that so many of those mufflers are actually louder than the DYNOMAX Ultraflows.

Thanks to all of you for your advice. I installed the 20 inch Dynomax Turbos and LOVE Them. They are MUCH less noisy and no drone. Plus, I swear it has more power.

I love the S/T's, got them on my 528" Hemi with TTI headers and 2.5" exhaust with x pipe. I like quiet and low key, stealth mode. Cops don't look twice at my car, but when you get in it, as a friend described it eloquently, "It sounds like you have a tiger in a bag and you are beating its ass!"

That's why Dynomax rocks!!!!