A Bursch exhaust came on my '73 2.0 when I bought it a couple of years ago.

I always thought it was a bit loud due to an exhaust leak I had (thanks for a both a stripped threads on one of my heads and a broken dog ear on that heat exchanger.

However, now that the motor has been rebuilt (new heads) and new heat exchanger has been installed and all exhaust leaks have been addressed, I'm still finding it too loud.

I recall reading that there were quiet Bursch systems and loud Bursch systems. If that's true, I suppose I have the loud version. It's a bit much for what's basically a stock car (the engine was a 2056 rebuild).

What's available out there new (or used if in great condition) that would be quieter, but not sound like a VW bug.

The 4-2-1 piping is what counts (in my book). I replaced the muffler with a similar sized but quieter one. I think it was from Edelbrock. New muffler gaskets too.

Can you dumb this down for a newbie like me? What is 4-2-1 piping?

The OG Bursch installed on your car has whats commonly known a "turbo" style muffler as part of its design.
These are chambered & fiberglass packed.
As they age can burn out that muffling material & get progressively louder as you are experiencing.
If you are not a welder any competent muffler shop can replace that muffler section with new in about .5 hr for not too much $ to reduce the racket.
I stock the actual muffler (though Im not sure its on my site) to renew it.
As an option they (friendly neighborhood muffler shop) can add (bolt) flanges to update the header to a convenient DIY component that if you desire can be tailored with the specific muffler of your choice (there are literally tens if not hundreds to choose from shops like Summit or Jegs).
Ive done this on the Bursch's Ive owned.

https://pmbperformance.com/products/stock-m...rsche-914-72-75

2 pairs of primaries merging into 2 secondary pipes that merge into a single pipe that goes into a single entrance muffler.

The original exhaust was 2 pair of primaries directly connecting into a complex muffler.
Different versions/manufactures might handle the inner flow paths differently.
It's not an open log internally.

If you had all 4 primaries go to a single collector, you would call that a 4-1. My old school Bursch in like this.

Stock muffler with SS polish tip

Looks good slightly sticking out under the rear valance, follows the body line, quiet, was designed for the car. I have been happy with mine for many years (quickly trashed the Burch that came with the car). I have a 2056 D-Jet.

Wasn't there a comparison test between a few of the classic aftermarket systems, and the stock one was pretty much best on overall RPM range for ~stock application? 4 in 1 on built engine are obviously a different story.

By overall do you mean across the band or that its gains in some places made up for weakness in others? I am tempted to go back to the banana but I would hate to lose anything up top.

I thought I had read a comparison at some point but I can't find it.
Maybe others remember?