I have round glass pack looking turbo mufflers on my slant. Seamless and the exhaust guy said they last a long time.

They drone between 55-70 mph with an H pipe. 70+? quiet!

X pipes require lots of dyno and AFR etc testing. H pipes just get it as far forward as possible.

H pipe cut the noise some.

_________________
'72 Duster 198 stock cam, 3:23's Hookers on jack stands for 8 years in the driveway
'79 Maxivan 360 Offy Qjet Comp RV cam/rusting in the driveway.
93 D350 160HP Cummins Auto Dually Clubcab needs a injector pump
2005 Golden Couch Buick

Sandy, I suspect your rear pipe is just enough shorter than the '67 and up A bodies to have a different resonant frequency. That plus maybe the over dirve tranny puts you at a lower RPM at cruise. Maybe even the tune on your engine has something to do with that. I discovered that the leaner mixture at cruise made less noise. And, timing effected the exhaust note as well.
Sam

_________________

....I think its the larger muffler.

_________________
Yeah....Im the one who destroyed this rare, vintage automobile.....

Which chambered pipes? The Formula-S cars got ordinary exhaust systems with ordinary reverse-flow mufflers...and a resonator in the tailpipe with a racy-lookin' big square angle-cut outlet end. I think Ford experimented with chambered pipes for a couple years.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

IIRC 302 Z-28's could be bought with headers in the trunk, and chambered pipes. '69 or so?

_________________
'72 Duster 198 stock cam, 3:23's Hookers on jack stands for 8 years in the driveway
'79 Maxivan 360 Offy Qjet Comp RV cam/rusting in the driveway.
93 D350 160HP Cummins Auto Dually Clubcab needs a injector pump
2005 Golden Couch Buick

Yep. Been watching MASH reruns too often!



CJ

_________________
Part of Tyrde-Browne Racing