Hi Paul,
there are two vanagon waterboxer engines that use an aluminum thermostat
housing..
the 1.9 waterboxer, or the 2.1 Syncro ..
It always helps if say what people are working on.

I happen to know you are doing a 2.1 long block with a 1.9 cooling system.
What your exact problem is, is not clear from you post , to me anyway.

typically those 3 1/2 long bolts that go thru your t-stat housing ..
get stuck in their long holes...
I've got a few 1.9 t-stat housing with that syndrome.
     They have several corrosion-related failure modes.

what do you need actually ?
I could sell  with one of the few useable 1.9 t-stat housing I have.

Scott
www.turbovans.com

On 8/19/2012 9:23 AM, Paul wrote:
> As luck would have it the two 8mm, I think, bolts that are on the opposite
> side of the temp sensors in the thermostat housing sheared off due to being
> seized in the holes due to lack of maintenance on my part. Anyhow I've
> managed to drill them out to the point where I don't want to use a larger
> drill bit and risk screwing up the threads. In fact in one of the bolts I
> tried using an extractor type bit that broke off in the bolt too. Any sage
> advice would be greatly appreciated. These are the last two stumbling
> blocks, that I'm aware of now, standing in the way of me getting my engine
> back in the van so we can go camping................
> Help,
> Paul in Tracy
>