Thanks David! 
I'll explore that possibility. I was trying to find a way to get it as close to the turbo as possible so it would be the temp from all 4 cylinders and that didn't look straight forward. 
Is there a "usual" place to install? And I've assumed stainless for the bung as it's easier to weld to cast, correct?

The engine was completely rebuilt about this time of year in 2010 (yes, part of my $20K) so I'm pretty confident that the bolts aren't all rusty and problematic. In general the manifold looks to be in good shape.

Regards, Peter Kraiker
nextchapter.kraikerphoto.com
Toronto, ON, Canada
'82 L Westfalia 1.9 TD 5 Spd (Babe)

On 2012-10-20, at 8:09 PM, David Beierl <dbeierl@ATTGLOBAL.NET> wrote:

> Peter, I'd think that your local muffler shop would be able to install a bung in place in about fifteen minutes if the pipe is sound.  Should be able to weld the bung on and then drill through the middle.  Might need a right-angle drill to be able to get the bung up onto the side of the pipe without moving it.