So they weren't horrible and cheap sounding?

I ran 3-1/2" Dynomax Race Bullets and they sounded like open headers. Tried the larger case welded (straight through) mufflers and I could still set off car alarms at idle. Sounded like a bunch of loud motorcycles. Finally git the 3" TTI exhaust with large Dynomax Turbo mufflers that come with the TTI kit. There seemed to be no change in performance, but now the car was much quieter.

Drone = Flowcrappers!!

I ran 2.5" HOOKER Aero Chambers on my 340-6 in my 81 Shorty for years. It sounded great and got lots of good compliments on the sound.

I run a full exh out to the rear bumper and its a 3" TTI system with an X-pipe and Ultra-Flow mufflers. You can here it in this clip as its not to bad at all to me. I can listen to my radio with no problem cruising along. Since I race my car I wanted a good flowing straight thru muffler and the Ultra-Flows are very good mufflers for performance. Ron

http://www.youtube.com/watch?v=bYIM2HLaOI4

Thanks for the replies and videos. Mine is a stock 340 I always liked the sounds of the 69 z-28s and 375 horse 396s that had them when new. It had a very crisp sound, I'm not sure the solid lifters had had a lot to do with it. I will try them , thanks again.

I have figured out that I want to run the TTi 2.5" X-pipe dual exhaust (with muffler eliminator pipes in place of where you would order mufflers under the rear seats) bolted onto my existing TTi headers/2.5" collectors. This gets me from my existing 2.5" collectors all the way to the rear bumper and I can add the Accurate SS 2.5" R/T tips. Then I can measure the straight section of pipe beside the gas tank and see which length of muffler would best fit the area.

I am thinking that If I use the X-pipe, I might be able to get away with the Magnaflow 6" diameter SS mufflers (14" or 18" long) beside the gas tank (in place of the existing OE style 7" x 18" mufflers). Then if this is still too loud for street driving, then add the Magnaflow 4" diameter SS mufflers under the rear seat (acting resonator)where TTi places the muffler eliminator pipes (18.5" long).

This should give me the straight through 2.5" exhaust and quiet it down for the street while using SS mufflers and SS R/T tips.

Thanks for all of the replies.

The TTI exhaust uses a offset inlet / center outlet muffler, so your elimination tube will have to be offset or angled for the tail pipes to be in the correct location. If you have a stock gas tank there is not alot of room for mufflers on the sides of the tank.

The elimination tube is TTi's design. They just call them ""2.5" x 18.5" MUFFLER ELIMINATOR PIPES w/ ID SWAGE ENDS"". So the exhaust should bolt up just like their muffler was in place.

My current OE mufflers are 7" diameter and they have offset-inside/center 2-1/4" pipes with the stock R/T tips. I am using them as a reference and I have take dimensions from the center line of those mufflers to the frame and the tank. Referencing their online pictures for Ebody tail pipes (attached) and knowing that other members have welded in 4" diameter mufflers in the stock position, I am hoping to stuff as big of a muffler in there as possible both diameter and length. I think a 6" diameter will work but if not, then Magnaflow makes a 5" diameter too.
Once I have the TTi muffler elimination 2.5" exhaust in place (with the R/T tips installed), that should show me exactly the muffler space required. Then is it just calling up my local Oreillys and having them order me a set of that size.
If the noise is too much for my streeter, then that muffler elimination tube just might get a shorter 4" muffler mounted to it to help as a resonator.

Thanks for your reply.

Y07_A66:

I recently added Magnaflow 7" round X 14" case mufflers (3" pipes) behind the axle to my 70 Cuda. I do not have the Cuda cutout valence, so with the turn downs the mufflers need to be positioned a little lower, and are slightly visible from the rear of the car. The exhaust work was custom bend, but I was surprised by how much room there is, at least for a 14" case. If I had the cutout valence, I believe everything would have tucked up very nicely, and I might have been able to run an even longer case.

I run these. http://pypesexhaust.com/i-13475154-race-pro-muffler-14-3-off-center-304ss-mvr19s.html

Dave,
Thank you very much for the picture. That is the first picture that I have found showing the MF round mufflers beside the tank.
I am surprised that you were able fit a 7x14 in there! Once I have my exhaust purchased and installed, I will cram the largest one in there because I am hoping to not have to use a resonator under the seat.

Do you have another angle of the 7x14 in there? How close is it to the bend on the over-axle pipe?
Have you tried your exhaust with only the round mufflers?
If not, is it loud now with the set of MF's on both sides?

Thanks allot!!

I'm late to the party here, but why don't you want mufflers under the car and only at the back?

I do not want mufflers under the rear seat due to ground clearance. We have speed bumps around our area and I don't want to have to worry about them.
I know the factory did this and my car used to have the resonators under the rear seat. But I want to see if I can put a large enough round muffler (thru style) beside the tank without having to add the resonator/muffler under the seat. This is why I will go with the x-pipe to see if that helps bring down the noise too. Worse case and it is too loud, then I will add a 3.5/4" round muffler under the seat.

Y07_A66:

The few photos I have right now are from the rear of the car. I hope to get the car out this weekend, and can snap a few other pics from showing the area between the axle and the tank.

Prior to adding the round MFs, only the oval Ultraflows were present. Everyone's view of "loud" seems to be different to me, and as you know there are many factors that will affect the sound level. My car has full 3", an X-pipe, headers, 400/470, and cam of [Email]248@050.[/Email] My tolerance has gotten lower as I have gotten older, and originally I felt the car was "loud" (as in the family knowing I was home before I even pulled into the driveway). Even now, you can hear it while idling in the driveway while inside the house. You have smaller pipes, less displacement, and less camming so you might be OK, depending on your tolerance. A straight thru muff isn't very quiet in my opinion!

The additional of the MFs did reduce the noise by about 10dB at some frequencies in some positions. My car was actually loudest by the rear wheel wells. Do you have a smart phone? If so, look for the "FrequenSee" app. I'll attach some before and after plots so you can see the impact. Here is the difference from the driver's side. First pic is UF only, second is UF + MF.