All the major vendors sell headers. I would say the two major header dealers would be Wilkinson and Precision Proformance.
Wilkinson says he has dyno tested the new stainless ones and it shows it has fixed the big loss through the original mufflers.
Ask him for the printout. He won't show it to me.
Something about the original mufflers having a 1-3/4" restriction ring internally and he removed that and put in a 2-1/2" ring.
That's the mufflers.
Even the GTS European headers give away low and mid range even on a stock engine. The tubes are too short and there is no collector.
I'm not sure what the thinking was on them originally. Maybe just that they sounded and looked right for the time?
There is a guy who makes muffler inserts to fit into the Cobra side pipes to quiet them down. The can be cut to any length and take the edge off of the loudness.
They are about $100 each insert.
You could use those in the Hall Big Bore setup.
I haven't tried them yet but are on my wish list for my 3" stainless 21" glass packs on my 180's.
Those make the same power as straight open pipes but they are almost as loud as them as well.
In the cabin you don't hear them unless you are going through a tunnel and you can hear the car coming in the distance like you would hear a race car on a big track like Daytona.
It isn't too smart to draw that kind of attention to yourself here.
The NYS "mounties" are not kind to you and don't appreciate the disturbance to the peace. Makes them stop you and start looking over the car for other types of attempts at anti-social type behavior.
Frankly I hate a 5'2" midget in a Smokey the Bear hat strutting around the car with his hand on his side arm, younger then my mid 20's sons, and being called Douglas, just like my mother did when I was being lectured.
Something about the attitude when they pronounce the D in it? Grrrrrrrrrrrr!
Must be something in the state statutes that for every 2 minutes of his time he has to write you a $125 ticket? It gets really expensive, really fast.
When my kids tell me, "Dad, the car is LOUD", that should be a yellow caution flag and can't be a good thing?"
Gotta put in those sound deadeners...