My '55 Tbird has a stock 1 3/4" through bumper exhaust system purchased in pieces from NPD.  The exhaust manifolds are stock cast iron 1957 TBird. It's too loud, rattly and full of exhaust leaks.  I am in the process of upgrading my exhaust system and could use some feedback from other TBird owners. I found an excellent exhaust shop that can do the job. I am thinking 2" pipes all the way back. Should I run standard mufflers or glass packs?  How about resonators?  Should I keep the through bumper pipes?  I like a car with a good muscle car sound, but not too loud or distracting. Thanks!

2 inch tail pipes are a good idea, but I doubt if they will fit through your bumper guards.  Below the bumper outlets probably will have to be used.  If it is too loud as it is, then glasspacks would probably be too loud.

John - "The Hoosier Hurricane"

I have a 55 Tbird, and I plan to run 2 1/4-inch mandrel-bent pipes all the way back and through the bumper guards. If you look at the bumper guards, you'll see there is a removable insert, in addition to the round tailpipe hanger. The hanger probably won't work on 2-inch pipes, but a competent shop should come up with something that will. Aesthetically, the larger pipe should somewhat compensate for removing the insert by reducing the gap between the tailpipe and outer bumper guard. 

I would not bother with installing 2-inch tailpipes if it means having to route them under the bumper.

The bumper guard insert inside diameter is 2.37 in. The trunk drop-off/valance holes ID is 2 11/16. Only the hangers, which fit tightly around the tailpipes, will be an issue with 2" pipes. Again, a competent shop should come up with a tailpipe hanger that will secure the tailpipes and keep them from rattling around inside the bumper guards. If someone wanted to run 2 1/2-in. pipes, the insert, which is attached to the back side of the bumper guard with 3 screws, would have to be removed. 

I've run 2" exhaust on my 55 for many years now. If you remove the back bumper first you can easily access those exhaust clamps that are in the bumperettes. These can be modified to fit to accommodate the size pipe you select. I think much more than 2" may be overkill, but it's your choice as to the mods to your engine. And to the selection of choice of mufflers, you can buy. I used Magnaflow and mounted them behind the factory position. This requires a shorter muffler and proper entry and exit points on the muffler. Magnaflow provides options for various locations.  They also have different noise or sound type levels available. The one I chose is more metallic sounding than I prefer but it is OK, I'm not changing it now.
I highly recommend checking out the repositioning of the mufflers. The difference on the floor temp is well worth it! In the stock position, your feet and passengers are right on top of the mufflers.
If I had to do this over I might have selected a quieter muffler. But heck its hard to decide without actually running them and changing them out. I didn't' want to throw more money at it. It still sounds good though.
As mentioned before you will want to find a competent shop to work with you on this. My experience was not the best and I redid some fitment things like they should have been done in the first place/Here are some photos while I was doing some other work on it at the time. I wish I could say my Bird looked a lot better underneath.

If you are interested I can dig up the info on the sizes, etc.

       A  L  A  N   F  R  A  K  E  S   ~  Tulsa, OK    

My bird is 2 1/4 back from the FPA headers. It does not exit thru the bumper. I used Hushpower mufflers, and they’re way too loud. I ended up adding resonators behind them and it’s still marginal. I’ve got another similar car with the older, standard issue Flowmaster, it’s pretty good. I should have used them on the bird. I’ve also got several friends with Smithy’s. They all sound good and are reasonably quiet while being “sporty”.

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

Thanks for the feedback.  I found the best muffler shop in my area and have an appointment on Thursday.  They are going to use 2" pipe all the way to the bumper.   I have had Magnaflows before and I like the sound, so that's what I'm using.  I am not adverse to noisy hot rods, but it doesn't seem appropriate for a TBird. My pieced together NPD exhaust system just isn't getting it done.

Phil, ask the installer about putting in an H/crossover pipe. It's supposed to balance pipes, reduce drone, and provide a lower, deeper exhaust note. The H-pipe usually is 2/3 diameter of exhaust pipes. A Youtube video recommends placing it just aft of the front u-joint, doing double duty as a driveshaft loop in case the u-joint fails. Personally, I've never had a driveshaft let go. 

Picked up my TBird at the muffler shop yesterday afternoon. What a difference!!  He used 2" pipe and hung the Magnaflows behind the stock location like Bird55 pictured in his post. The sound is sweet music. Ever since I've had this car it's had a crappy exhaust system. The new system changed the whole driving experience. Thanks again!

That's awesome - I understand where you're going with this. Is there a crossover pipe incorporated in the system? 

64F100 57FAIRLANE500