I had a heater cable break on me, broke just before the fat end that connects to the barrel bolt fits in. Was wondering if the cables are the same through the years or are they different lengths through the years.

Who out there sells heater cables. ö¿ö

As a temporary solution you can get a heater cable repair kit from a VW shop. It is a replacement end with set screw to clamp the cable. I have one on my car (temporary means 4 years and counting - guess I should look for heater cables also)

I'd imagine that Auto Atlanta or GPR would have them. The temporary fix should also do the trick.

Different length cables for the last two years (I think)
When I backdated my heat, the flapper boxes never quite closed the same way.

The heater hose extending from the firewall is significantly shorter on the later models, placing the flapper boxes in a different position than on the early cars.

Since the flapper boxes have the springs in them, I thing that a stiff spring steel wire (music wire) is not necessary. What is to stop you from using a flexible wire cable? This would be readily available at the hardware store.

Strange. I backdated my 75 and did not encounter this problem. If you get the left and right flappers switched, you will have the problem

Prolly nothing but the OE part is also plastic coated either for corosion protection to avoid the wires rattleing in the tubes or simply to make them more slippery