I actually have already replaced most of the exhaust hardware on my Westie
('85 1.9L) with stainless steel, and have been able to remove/reattach the
cat and muffler without any problems (replaced the useless CIP muffler
strap with Terry K's far superior part).

Two things I made sure of:
         - Use anti-seize on assembly.
         - Don't over-torque.

When I first disassembled the exhaust, there were already some stainless
fasteners on there (where the headers meet the collector pipe), and these
came apart with little trouble, any non-stainless bolts were rusted to the
point where they came apart by snapping.

YMMV, depending on the age of your van and your climate. :-)

Tim

At 12:34 PM 1/17/2007 -0500, Geza Polony wrote:
>stainless steel bolts on your muffler/catalytic converter.
>
>The more experienced among us know this already. I thought I'd beat the
>corrosion problem by using M8 stainless bolts and nuts for my new Bus Depot
>cat and muffler. Once they heat up, there's no way to loosen them. I don't
>know what happens to the steel, but it sure isn't any labor saver. The heads
>just break of when you crank them.  So much for good intentions.