Heater box replacement

Does anyone have any suggestions on how I can get the heater system to work with a custom exhaust on my '70 Squareback? From the pictures and videos I've seen on the web it seems that you have to go back to the stock exhaust system to get the stock heater boxes to work. I've also seen what looks like custom heat exchangers on a custom exhaust system but I can't find anyone who sells them. Any ideas?

Um, what's the "custom" exhaust, and how much of it is different? There are dozens of aftermarket exhausts available. I have a Monza on one of mine with functioning stock heater.
If the exhaust header is different, and IF there are boxes available, they're likely going to be found using the brand name as a search tool.

Truly custom is reworked or fabricated from scratch.

I have a Monza on mine and it retained the stock heater boxes. I love the sound of the exhaust too, especially when the engine's cold and it lopes like it has a cam. <3

The Monza is a good sounding muffy and not obnoxiously loud or anything.

Thanks for the input, guys. So I think I have a more fundamental question. The car did not come with any heater boxes so I don't know how the heater box/exhaust configuration was originally set up. From what I can tell is that the original muffler had pipes that fit into the heater box via an elbow into the muffler. If you purchase an aftermarket muffler where does the heater box (exchange) get the heat?

Maybe a diagram would help me understand here.

The heater boxes aren't affected by the muffler. It may not make any difference as long as the connections are the same.
As long as the pipes out of the engine (exhaust manifold) are stock and the new muffler/exhaust parts don't interfere, the heater boxes should fit on.
Then you just hook up and adjust the cable ends (in the "off" position) and install the connector tubes to the body and you're in business.

Here is a photo of one installed. They are often replaced with the simple "J tubes."

Heater box installed.


J tubes. No heat.

Now I get it! This may sound funny but I did not realize that the j tubes replaced the heat exchangers. Thank you for the aha moment.

Just things you know when you have a VW that everything works on.
These cars are so easy, there's just no excuse for not having working horn, dome light, wipers, etc....
No heat I can understand above 1776, but there's nothing like having heat on a cool day with the sunroof open, or to dry up a damp interior.
Nice to have a light come on in the dark when you open a door. Weirdly, the dome light is the easiest circuit in the car, and one of the most often non-working items.