What type of exhaust does your 273 have??? show some photos!!!

Just so you know,
back in ~1999, I bought a set of Nickle-plated TTI headers for my 68 Barracuda/367/4-speed/3.55s, and their full length dual 3"exhaust; which, fit like a glove. Yeah it was tight, but it fit. IIRC, I paid a lil under $1000 for the system.
For the install; I started at the back, and all joints are slip fit. The TTI clamps are just suspending the system.
Eventually, I installed a couple of sheet-metal screws to index the TPs to the mufflers, cuz the TPs had a tendency to rotate. The 3-pass Dyno-max mufflers are hung from the rear seat-belt bolts, straight down..Honestly, the install was a breeze, on the 68.
A couple of years later, I moved my springs over with the 1/2 kit, and narrowed my rearend. That didn't seem to affect it at all.
Just so you know.

But to install a GVod, I had to cut out the "H". The engine immediately lost bottom-end torque and I really noticed it. But I loved the new sound. My solution was to replace the standard 2.66-low Mopar box, with a 3.09 Commando box. Problem solved.
If I had had a smaller engine; IMO, that would not have been enough. I would have re-installed the H, a lil further down the line.

EDIT
But yeah;
> dual 3" would be overkill for a 273.
> I'd still run it.
> it's heavy. IIRC about 75 pounds from the headers back.
Is it loud? Only at WOT.
Is it annoying? Only to the neighbors, if I roll in late at night.
Does it drone? IDK; Not at 65= 2240rpm. I can't recall from before the GVod, but one would think, I'd remember if it did.
Yes, for the most part she has run the 3.55s since 1999, with brief stints of just about everything else.
My stock long-block lo-compression 318 4V loves the dual 3s, and sounds real good with it, too.

Funny story
Some here on FABO have the impression that I am a 318 hater.
That ain't true.
I just like annihilating tires with my 367.
I used to run a 318-4v every winter. and I would run various transmissions behind it, before introducing them to the summer motor, the 367.
One winter
I was running the Mopar A833 with the GVod behind it, and it was set up for gear-splitting. This provided Seven progressive very close ratios, with a double overdrive. I ran 2.76s for a while, in the back. The carb was a big Thermoquad, on a small-port intake.
SO
What I liked to do, was to rip thru the gears at low rpm, and let that big TQ roar. I mean this was a 150 hp engine, so puling something like, 2200 to 2800, it takes about 17 minutes to hit 65 mph , roaring the whole way.
I loved it.
With that combo, 65 was 2240rpm in double od, lol . With the 3.09 low in the trans, 2.76s takes off like 3.23s with the standard 2.66 box. Eventually, I tried this with up to 4.30s, which cruised at 65=1840 in double-od, and takes off like it has race gears.
Here's the point,
for a streeter, gears makes or breaks the combo, and since I loved the roaring TQ on a 318, for winter; I would love to try it on a 273.
I know pretty much exactly how I would build that combo.

Now, I know you want to keep your car more or less a tribute car, so the above may just be anecdotal, but, if the 273 gets to feeling a lil sluggish down the road, I got an automatic story I can relate, too. I swapped these engines around every spring and every fall 5 or 6 years in a row, so there's almost no combo I haven't tried.......... and you know, a 273 is only a small-bore 318............