I have a 1969 442 with the 400ci engine, what is the stock exhaust diameter, Head pipes and tail ?
Also if i were to install Flowmaster mufflers, would it be the 40 series.
Thanks.

 

Neil that famously distinct Flowmaster sound comes from the 40 series 2 chamber muffler.

 

The (no)Flowmaster has the distinction of being among the most restrictive aftermarket "performance" mufflers in published tests while simultaneously being among the most annoyingly loud and obnoxiously droning. That's no small feat. You might want to rethink that choice.

 

What about Magnaflow mufflers.

 

Neil I've had 2 chamber 40s on a 1967 330 Cutlass with headers, 1966 400 442 stock manifolds, 1987 307 442 stock manifolds, and currently on my 69 350 stock manifolds. So to say I disagree with Joe P may seem like a huge understatement. What I will say is he has merit but this is a subject with several layers to it IMHO.

Do they perform worse than most other performance mufflers, according to test results I have seen yes. But they also perform much better than OEM type mufflers.

I have always heard about the droning, but if its there it doesn't bother me....

Are they loud, yes with headers. Even at idle I would have to turn off the engine at a drive-through.

Now the knocks on Flowmaster have been around forever. So you have to ask yourself why do they sell so well.... Because they sound great !

Nothing sounds like them, think mean deep urgent guttural metallic bass. No question it helps a V8 sing an ornery song.

Build quality is through the roof.


Here is Flowmaster.


Here is Flowmaster unleashed.

 

Here is a comparison that may help.

https://exhaustsystemsguide.com/magn...vs-flowmaster/

 

Exhaust sound is a very subjective topic. Of course, the longer you drive with (no)Flowmasters, the better they sound - kind of in the same way that the more you drink the better I look.
Seriously, they are obnoxiously loud and annoying. There's no reason to **** off the neighbors while making LESS horsepower than you would with a less annoying muffler.

 

Thanks for your input SCHC.

 

My pleasure, pure fun in a sense. Talking about this stuff and digging into it, is akin to seeing a good movie again with a friend who has never seen it. Sometimes you see it through their eyes, the experience is almost as satisfying as the first time around.

Annnnd Joe will not hear of it, no pun intended.

With regards to the sound being subjective, absolutely. I love it others may not. I guess in a perfect world you'd want a muffler that is oem quite at idle etc and loud when you stomp the go pedal. 40s are definitely not that. They go loud to louder. But again reasonable with stock manifolds IMHO. My take on Flowmaster is your paying for its unique sound multiple times, once when purchased, again with regards to slightly more HP consumption than other performance mufflers, and a third time because the sound is always "on".

Have a friend who had a 71 Nova SS that ran great, had headers and IIRC Dynomax mufflers. They did the mellow to aggressive thing when gotten on. He was happy, myself I like a more aggressive overall sound.

P.S. Joe you may be really onto to something though, because I haven't wanted to go back to headers since I first went that route. One reason being clearance is always a concern. The other being that I remember them being LOUD. I'm about 20 years older now and tastes definitely change. But I still love the 2 chamber sound.

 

One more angle FWIW here. We have 2 Olds in the family - my blue DX w/ Super Comps, 2.5” X pipe to long case Dynomax & full 2.5” tailpipes vs kid’s red 350 with Comp small tube headers & the same system out the back. His car has always been noticeably louder than mine at idle & normal driving, not sure on WOT. We just replaced his headers, mufflers & tailpipes with same as they rotted out after 10 CT winters & it still sounds the same as the original installation. When his car first hit the street for a short time it had the X pipe system with OE manifolds & that too was louder than my car, go figure.

Im a quiet to moderate sound level guy - Captain Obvious