I think the metric size is 10mm, but I've never had leak troubles
using standard US 1/8" pipe thread fittings(brass) from NAPA or other
vendor and putting red or blue loctite on the threads(cleaning the
female block threads with solvent and a stiff tooth brush.

.....but then I've never intended to re-install the factory OP switch
in the block hole either. YMMV

DM&FS

  12:10 AM 5/5/2007, Nathan Mc Blain wrote:

>   Could anyone please tell me what the exact engine case threads
> that the oil pressure sender screws into.  I would like to make a
> temporary gauge, to see what my current oil pressure is (latter on
> I'll do the real deal).  I want to order the hose fittings or pipe
> to attach to a hand held gauge.  I though it might be tapered
> threads but the pics at vendor sites looks like it is straight metric threads?
>
>   Thank you much,
>   Nate