Aaron Wood wrote, with respect to mounting an oil pressure sender on his
engine,

"....So on to plan B, I went to the harware store and bought a two inch piece
of brass pipe and a brass "T", all having 1/8 in NPT.  I screwed the pipe into
the existing hole, screwed the "T" onto the pipe(so that there was on
horizontal and one vertical hole), screwed the original idiot switch into the
top hole and the new sender in the horizontal hole.  Everything fit just
great. 
 
.......To sum it up it looks like the strangest contraption in the world.
The new sender mounted horizontal, the old switch mounted horizontal, and the
bleeded valve on top."

Although this solves the problem of attaching the oil pressure sender to the
engine, I am not sure it is a wise idea.  The sender, T and associated
components represent a substantial mass; all of which is hung out 2 or more
inches off the end of that brass pipe.  The "contraption" is a pendulum
fastened to your engine.  Engine vibrations will be magnified at the end of
the lever arm (the 2" pipe) and will tend to shake things loose.  If anything
gets the slightest bit loose it will start pounding the hole (into which it is
installed) and damage the threads (although it will probably leak
objectionally before the threads are damaged too much).  All in all, it seems
like a risky mechanical design.  But I'm not an expert, so I'd appreciate
comments from others on this since I am facing the same problem; how to add an
oil pressure sender without having to remove the engine!

Brian
miller@spk.hp.com
'72 Type II
'80 Vanagon