I currently have the 6=1 MP header, I already have the clifford duals and planning on throwing em in tomorrow. I have a single 2 1/2" tube now dumping at the rr end with a 50 series 3 chamber flowmaster and it has a high resonance. Its my daily driver, gets on my nerves. I have a set of factory replacement 2 1/4" Hemi Mufflers. I have a head in the works for getting a total bowl job I SAID BOWL....LOL...I have 3.23 peg, 436 MP Cam 4bbl Holley 390 and bored 40 over. What size pipe should I put on the car. Mind you it will be dual exhaust and running to the tail of the car. Just looking for something to give me the right back pressure, How do the Hemi Muffs sound anyways? I am hoping silent at idle and rip roarin when I stomp on it. Also, Should I run an H-Pipe?

Pete

Since the muffs are 2 1/4, I would run 2 1/4 from the headers to the muffs, then step-down to 2 inch to go over the diff. and out the back.
I would run the "balance tube" (H-pipe) just to help cut down on the noise.
DD