One of my new definition words since I've joined this forum is drone. Drone is a vibrating, rattling, humming noise at various speeds directly related to some exhaust setups. Watch out for drone, it drives people crazy.

Not rocket science here.... Come to the BASH and listen to, and ride in, a bunch of cars and copy the one you like best!

I have a bone stock A code 289 with 2.25 pipes, stock h pipe, flowmaster 40 mufflers, and GT baffles through the rear valance.  It sounds pleasant, makes a little noise when you mash the skinny pedal, but I can sneak in the garage without anyone knowing I'm home, and no drone.....

My neighbor has a 65 FB with a warmed up 289, tri y headers, and 2.5 pipes out the back.  He had FM 40's for about a week, and switched to FM 50's.  That car is still LOUD, to my ears.  My simple mind would say that larger diameter pipes, and a performance oriented engine build will affect the volume.  Try to find a SBF built similar to yours, that has a sound you like, and clone the exhaust.

I've got a warmed up 289 in my 66 with Hedman long tubes and Flow Master 50s H pipe 2.25 dia aluminized pre bent from Summit. It has a nice sound to it although I would like it to be a little louder but that's just me. I've always liked the sound of my sons 04 GT. I think he's running FM 40s. I should mention mine has no drone at highway cruising.

I left out that its mild 302 with a little cam and hooker long tube headers.

Thanks everyone for the feedback.  I think I'm leaning toward 2-1/4" aluminized with an H-pipe mad to fit the TriYs I have.  This is the kit that seems the closest to what I need:  http://www.cjponyparts.com/dual-exhaust-kit-2-1-4-inch-for-use-with-tri-y-headers-with-flowmasters-289-302/p/EXK11BF/
Here's a picture:

I called CJ and they told me that the kit comes w/ Flowmaster 40s but I could substitute 50. They also have a similar kit for Magnaflow mufflers, and lower priced kit w/ stock type mufflers. Thoughts on that?

Also, I asked if the kit would work with thru the valance exhaust like the GTs had. We pulled up a kit for the GTs and the portion to the rear of the axles looked similar:
http://www.cjponyparts.com/dual-exhaust-kit-gt-v8-original-1965-1966/p/EXK1A/
And here's that picture:

So it looks to me that the the kit I'm interested can be routed thru the valance.  Thoughts on that?  Thanks.
 

HenryJ wrote:

I would personally take it to a muffler shop. We have several good one's in my area, so the decision is an easy one for me... especially since you have a t-5 with tri-y header's.

HenryJ

X-2!
 

I've had the Summit Universal Kit with the Summit Headers for at least 20 years.   Still in good shape.  I added Magnaflow mufflers a couple of years ago.   Touch up the headers with some paint every couple of years.  Steve69

Been over 20 years and never a muffler problem on my 65 Fastback! Oh Yea, I don't have any mufflers. 

True74yamaha wrote:

Depends on how loud you want it. My 289 65 coupe has an h pipe and super 40 flow master and under valance exit. It sounds mean no where near as loud as a guy I knows 74 rancherito ranchero with a 351 which has an x pipe and optional dumps. I do not know how he can stand his car. Mine after a while the drone will drive you mad. If you go for long drives its even worse. If you want a good sounding quieter muffler you might want to go with the magnaflow mufflers or exhaust kit.

Choosing mufflers has got to be the biggest crap shoot in building a car.  I always end up swapping them out a few times before I land on the ones I want.  I think I'm leaning toward the Dynomax super turbos. 

One of the best ways to keep exhaust drone from happening is to stagger the position of the mufflers --don't have them both side-by-side the same distance back from the headers/manifolds.

Exhaust drone was a problem for the engineers when the SN95 Mustangs were being designed. To resolve the problem, they staggered the mufflers --one about 2.5"-3" ahead of the other.

Notice the pipe/flange to the inlet of the left muffler is a few inches longer than the right side of this SN95 exhaust system.

I am a fan of the Magnaflow system.  I got mine from Amazon of all places and it cost only $525! All stainless!  It comes complete.  I had to buy the header pipes and they were only $125.  I had my muffler guy install it and he welded all of the connections and modified it so that it can come out in just two pieces if I ever need to remove it.  It sounds great!  I am running my stock manifolds and not headers.