I've been using stainless steel for all exhaust fasteners for many
years with good results.  At the heads of course you need the proper
metric size and thread pitch.  At other joints you can use the less
expensive 5/16 SS from your favorite big box home center.
   When I was in Chicago I found a little speciality place that had
the SS metric fasteners.  Now I would probably go to We$t Marine.  Use
a little anti-seize when going into the aluminum head.

Larry A.

On Mon, Nov 28, 2011 at 6:06 PM, Gregg Carlen <gregg.carlen@gmail.com> wrote:
> So, while doing the head on my van (1990 2WD Westy), I was able to 'safely'
> remove the header bolts and nuts between the exhaust and head. Of course,
> these are one-time use hardware. Aside from just using 12 and 13mm nuts and
> bolts, can anyone recommend good quality hardware that will stand the test
> of time to use on the exhaust system so the next time I have to remove them
> for whatever reason, that I have a better chance of safe removal?
>
> Thanks,
> Gregg