Chris - I have a pair of Inconel mufflers on my '76 GMC pickup,
fabricated 13 years ago by a buddy who worked for Combustion
Engineering!  This is the one variant of stainless steel that they used
in the innards of nuclear plants to carry, uh, "hot" water.  I've had to
replace the exhaust pipes twice in this time, but the homemade mufflers
still look pristine.  They, of course, look like regular mufflers, but
have nothing inside!  Here in TN, no self-respecting hotrodder (or
Harley driver) puts real mufflers on their vehicle.

Me local Bubba Muffler Shop dude is willing to fabricate a set of
headers & pipes & muffler from this Inconel material for my Vanagon 2.1L
for $200, with me providing the material.  He's even going to set it up
with a "diverter" pipe forward of the "muffler", controlled via a
solenoid so I can choose between a true "straight-through" open pipe OR
through the gutted "muffler".

Catalytic converter?  Nah, as long as the predominant wind currents
deliver our polluted air into Canada, I'm not worried about CCs.
Besides, TN doesn't require them!

Chris, I'm a real believer in returning the crap we get out of the
ground BACK to where it came from.  My main concern about leaking oil
from my van has been that it really messes up my paved driveway and
parking lot, which exposes me to lawsuits from folks who slip in it and
fall!  With all them oil wells in TX & PA, it does make one wonder what
their produce tastes like, though, doesn't it?

I'll file a report on my Inconel exhaust system when it's installed.

BOB - WA4RRN
'85GL - "Bourgeois"
http://www.proglobalwarming.org