Cheap, Good Not Too Loud Mufflers for your Single or Dual Exhaust A Body

I am not sure on that. Maybe.

H pipes are for V engines or V8's from what I understand.
I am never behind my car when I am driving it, so they sound fine to me.

I would be willing to bet they sound like that on any engine with a good cam and at least 10.25:1 static comptession with an even 120⁰ firing spacing on the compression strokes.