Looking for advice on exhaust system.

Syleng1 said
On the Demon 340 4speed I have I used TTI 2.5” and “H”pipe and the delivered kit mufflers- Dynamax. They fit awesome with the factory manifolds, clean and are a nice set up with factory tips.

BUT when I had the 3.23 gears the mufflers (I’m guessing) made a serious drone noise like a “won....won.....won” at lower rpms in 4th. Mostly like 50mph and 1900-2200rpm.
I changed gear ratio (3.91) and it went away. I could had been my cam - but the Napa exhaust and mufflers on there previously did not do that.

In my 66’ Barracuda with 318, auto and fuel injection. TTI “X” 2.50” system with manifolds, and 2.45 gears. When the car labors, same drone.... same mufflers.

I really love their exhaust but the mufflers are to me “just okay.” Order it with the mufflers you like.
Good luck!
Syleng1

Question on your Demon.

Syleng1 said
On the Demon 340 4speed I have I used TTI 2.5” and “H”pipe and the delivered kit mufflers- Dynamax. They fit awesome with the factory manifolds, clean and are a nice set up with factory tips.

BUT when I had the 3.23 gears the mufflers (I’m guessing) made a serious drone noise like a “won....won.....won” at lower rpms in 4th. Mostly like 50mph and 1900-2200rpm.
I changed gear ratio (3.91) and it went away. I could had been my cam - but the Napa exhaust and mufflers on there previously did not do that.

In my 66’ Barracuda with 318, auto and fuel injection. TTI “X” 2.50” system with manifolds, and 2.45 gears. When the car labors, same drone.... same mufflers.

I really love their exhaust but the mufflers are to me “just okay.” Order it with the mufflers you like.
Good luck!
Syleng1

Regarding your 340 Demon. The TTi website lists your application with turn downs on tail pipes. There is no other choice.
67-76 DART, DEMON, DUSTER, SCAMP & VALIANT Exhaust Systems (Line 1I-1L)
1IH-pipe with Mufflers, Turndown, angle-cut 2.5" $ 710.95 Part # A25M WM6776
Are these the ones you ordered and used? Did you cut of the turndowns and install factory tips? Were your tips factory or aftermarket replica such as the ones TTi offers for 2.5" ? Any mods required for proper fit such as bracket or hanger mods?