In year 1999, I installed a 3" full-length TTI dual exhaust with the long 3-pass Dynomax muffs, on my combo. (the fit was great). They're still on there, and still not rusted thru. And I still like them.
I've Final-drive geared that car from 1.97(double-od) to 5.38s, and it never had any drone with any gear, even with the H removed.
It has a lovely idle, an awesome WOT, and with the current gearing, she cruises at 65=2240 in GVod.It's been that way now since ~2004.
At Part-Throttle and gently motoring, going thru and by 2800rpm, the 367 is just coming up on the 230*cam, and the sound makes me smile every time.
Car goes 93 in the Eighth, without the exhaust, and I'd bet a dollar not much slower thru the cannons.
Never, since that day, have I had the thought, for any reason, to change the exhaust or the muffs; and Never have I been pulled over for loud mufflers.
But yes, that system is heavy. IIRC 72 pounds from the collectors back.
Happy Hot-Roddng
BTW
If yur wondering why I installed the 3inchers, it probably ain't cuz the 360 needs it. But ya know, there's about 3.5 to 4 ft of pipe from the collectors to the muffs.
Now, I'm no engineer, but I got a reasonable idea of how headers work, and a couple of thoughts came to me;
1) the 3inchers have 20% more cross-section than 2.5s, which I imagined should help inertial header tuning and the engine should pick up some torque thru-out the rev range. IDK if it did or not, but I sure can't complain about the torque. and
2) the 3 inchers also have 20% more radiating surface than 2.5s, which I imagined should help the gasses cool and become more dense, leaving more room back at the collector, for the incoming pulses. From stem to stern, that is a good amount of cooling area; and so 93 in the Eighth is pretty good for a small-cam 367
3) I imagined that muffs with 3" in and 3" out would present less of an impediment in the corners of the 3-pass muffs, to the now sort-of pushed-along gasses.
4) My car is a streeter, and WOT-Power is not really a thing, cuz at WOT,
it spins street tires to well past the speed-limit. But low-rpm torque is a thing for me, and it's super nice NOT to have to downshift all the time. And the torque is really great for passing. and
my car is a manual-trans, so no help from a Convertor. She spends most of her life below 3000rpm, so torque really matters.
Your stroker will have plenty of torque down low, so I imagine that none of these points would apply to it. But I can tell you this; as to back-pressure; there is no such thing it ever helping power-production. It may however help in the fuel-economy equation, by stalling scavenging.
and yes the 3inch TTI tailpipes easily snaked over the diff, and between the tank and springs, even after I moved the springs inboard with the offset hangers. No rattles either. Good-job TTI.