I know this is a set-up of sorts, where I'm actually setting myself up, but I'm looking for opinions! I know what opinions are like, sometimes, but I'm hoping that somewhere in this select crowd, one or more of you might have experience with the two brands of mufflers I am looking at: Flowmaster F40 and Dynomax Ultraflow. Or even a third possibility I'm unaware of. One of these are going to go on my 396, which will sport 3" tubes in and out, coupled to Hooker headers. I live in a fairly dense neighborhood with many children, so I'm looking for "impressive sound" but NOT "obnoxious sound". Back when I had this same engine in a 4X4 truck (many years ago) I remember it had a "throb your chest" low note that immediately told you it was a big block, but was definitely not obnoxious. I'm hoping to not have to keep changing mufflers to finally get there, so would like to hear from anyone who has experience here. We will be at the 'purchase mufflers' stage pretty soon, and until now, I had been trending toward Flowmasters, but I am concerned that they might prove uncomfortable for my neighbors.

 

Well a big block with headers big pipes and Flowmasters is going to be pretty loud.
I have Thrush turbos on my 78 Square body GMC with long tubes and it sounds pretty good but not obnoxious,454 big block and 2 1/2" pipes that turn down behind the rear axle. Not sure if they come in 3" though,why do you want 3"?
I had a Flowmaster on my '93 Z28,the car was otherwise stock not even headers and it wasn't exactly quiet,with headers and a cam it would have been pretty loud.

 

Well, when I talked to the Restoration shop guys, they indicated no difference in price, which leads to my internal standard that is NOT universally true, but still often is: "If some's good, more's better". Then I found this interesting video on youtube, which admittedly is a test on a much more animal motor than mine, but still makes a very valid point: I think you will enjoy viewing it, as they're actually dyno-testing 2 1/2" exhaust versus both 3", along with open header, using Flowmaster cans and actual exhaust bends, with Hooker headers on a 454. The 454 makes around 620 HP open header, and almost the same with 3", but 2 1/2" is not nice to it, both in HP and torque. Check it out.

 

I'm running Hooker headers with 3" pipe, into Dynomax Race Bullets.
I like them, but they are a lot louder than a turbo type muffler and it's hard to have a conversation with a passenger.
Here's a link to a video of it running: https://photos.app.goo.gl/83r4UjcgCvo5pM7v5