I used a street tee to tee the oil pressure gauge sender with the factory oil sensor.
I used a spade tap to get a signal for the tach.
I planned to tee into the factory water temperature sensor port, but the d@mn thing was metric. Curses! My Jeep CRD was the same way.
Plan B was to replace the front cylinder water hose with this. I used 1/2" NPT to 3/4" hose fittings.
Here is the contraption in place. It was hard to get it in there. Space is VERY tight on the bottom hose. I had a leak from the sender and had to retape it, but finally got it leak-free. I had to run a ground wire to the sender.
I connected the gauges to the senders and ran the bike. Everything worked except the water temperature gauge. It was pegged. I thought the ground wire might be touching the sender wire, but investigation revealed the gas tank fuel sender housing was touching the sender contact and grounding it. Curses!!
Here is contraption version 2.0. It is smaller and sets more under the backbone.
I wish I had done this to begin with. It almost fell into place and is more accessible than the other design.
There's a little hole on the left side. I don't know its original purpose, but the temperature gauge probe fits perfectly in it.