There's no guarantee but from ~1972 Porsche used a sacrificial(ie less corrosion resistant) alloy for the outer heater boxes. This was a safety feature as they wanted to keep CO out of the cockpit, The thinking was the outer would corrode before the inner and thus be repaired before the inner was penetrated allowing CO to enter the cockpit heat supply. Way back in the day before SS and other corrosion resistant metal was used owners would often install CO detectors in the cockpit as an extra precaution.

The advent of full SS made this all pretty much go away.

I ran European headers on my 72 911 with first a 2.7L then a 3.0L. Loved them but even when I was living in Florida, early morning drives were cold and constantly wiping the window to see out. I've run with the early M&K muffler two in two out since they first came out. The muffler gives you the sound not the headers.

Since I moved to Oregon I traded my headers for SSI and have been happy with them , still have the M&K, they are both stainless.

Thank you for the great info.

I originally bought a set of headers from Fabspeed and opted for the ones with Heat... as everyone had me worried about my windows fogging up in cooler weather.

Unfortunately Fabspeed didn't warn me that the heat option isn't compatible for 3.2 Carreras... so I have been using them without any heat.

Apparently I didn't need heat as badly as I thought I would... though I don't drive my car in the winter, as usually the cold weather is the beginning of another project to fix something. LOL!