Not to side track you Tom, but several guys here are quite happy with the Walker Quiet-Flow 3 Mufflers, part #21856.

One more thang............going from 2" pipes to 2 1/2" WILL make a diff in sound.  Be a little louder.
X/H pipes will change the sound too.  I found out (a little late in my case) that X-pipes tend to smooth out the exhaust note. Takes away (some of)the chop a snotty idling camshaft tends to make.
My advice......."Leave the gun.....get the canolies"...............
I mean uhhhhh......forget the X/H-pipes and enjoy the sound your engine makes with the 2 1/2" pipes
6sally6
PS......I realize I didn't tell you anything new.....butt I just wanted to get in on the post!

Just don't understand why you need mufflers!

I'm probably the only one on here running Flowmasters but I really like them. I put FM 50s on it because they claimed they don't drone and they don't! However they weren't quite as loud as I would have liked but I've noticed that as time goes by they've gotten louder. If you want loud the FM40s are the way to go. My son has them on his 04 GT and you can hear him comin a mile away. Mine has 2 1/4 pipes with an H pipe and long tube headers, 289 in a 66 coupe. So if you are willing to give up a little loud for a drone less ride I'ld recommend the FM50s.

I have the 40's and the last time I had my headers closed off.....they did NOT drone butt......I ran the pipes all the way to the rear bumper. When they dumped just behind the rear axle.........they were pretty rough.
According to tests...FM are  one of the MOST restrictive mufflers on the market.  So don't use them if the last drop of power is important to you.
6s6

bearcat wrote:

The only thing I don't like about the 40s is the drone, It gets old real quick.

 
That's why I went with the 50s. Not as loud as the 40s but zero drone and a really nice rumble.

Trust me... that’s a lot like Hold My Beer isn’t it?

I’m on another board where one of the members was a retired Chrysler exhaust system engineer. He said the Flowmasters were not very good. He had said the Dynomax flowed very well. He also mentioned what surprised him was the rolled lips on chrome tail pipe extenicost something like 5 hp

I would like to take a survey, because I have a theory on who likes their car to go down the highway quietly and who likes it really loud.

Have you driven your car on a long road trip, like going to a bash?  If so, do you enjoy loud mufflers that stifle conversation and create drone, just for the joy of hearing the engine roar?

Do you enjoy a quieter, more civilized, but still a performance sound?

My hypothesis is those who have really loud cars only drive them to local events for a short distance, and they enjoy hearing the sound of the engine more than a need for conversation.

I know we have one long hauler that goes for the loudness, even though others in the car don't care for it.  What is your situation?  I am not biased either way.  It is your car and you can have it as loud as you want as long as it doesn't wake me up from my bed!  I like loud too, for a few minutes, but can't tolerate it on a long trip.
Make a reply post and let us know what your preference is, and if you take your car on long road trips.  Like 300 miles or more in a day.

You can call me  weeny butt.....I cap my exhaust up when going on a long trip.  ALTHOUGH!..for short around town trips I prefer a....."more robust" tone!
6s6

rpm wrote:

The fit, finish and cost of my Dynomax mufflers was great. But being born in 1956, I didn't enjoy yelling at the passenger for them to hear me over the straight thru design of the muffs. That and a drone at 1k rpm convinced me to remove them. I'm sold on the Walker Caddy mufflers regardless of lost hp.

rpm, 56 for me too. Im pretty much in agreement with you.I drove my friend’s 66 that had Flowmaster 40’s with 2.50” tailpipe going out to the bumper. I couldn’t believe how loud it was. Between the drone and how loud it was like ice picks being shoved in my ears. At this moment, meaning I’m not at the point of buying them, only looking, the Summit muffler is in the running. I talked with a tech, he wasn’t sure who makes them for Summit but guess Walker. Both are made in USA. He said all the turbo mufflers are going to perform about the same.

I am concerned that they will be on the loud side. I would rather have something like the Caddy but I’m going to wait until I can get the H pipe and tail pipe in and see how much room I have. That’ll be the determining factor. I will see if I can mount mufflers at a angle to clear the floor pan but who knows on the radius of the tail pipe bends will take away room.

If it comes down to having to use a muffler with a body of 14” and over all of 19”, it’s not going to leave me with too many options.

Tom.......I had a pair of the Summit brand turbo muffs several years ago. They were pretty quiet even though they dumped in front of the axle. (no X-pipe)  So quiet...I swapped them for the Blowmaster 40's.
I have them installed now with an X-pipe and exiting at the rear bumper. They are NOT loud and no drone (my ears can detect). Now....I have added sound dampening in the trunk and  behind the back seat. Also under the back seat and double thickness carpet and that stick-on water proofing stuff throughout the cabin area as well as sound dampening in the doors.
You ever come to the beach I will give you a ride.
6sal6