Need wiring help with Cluster swap.

[87Bob]

I am swapping out a cluster with gages to one with gages and a Tach. The year of the Tach cluster is unknown it is going into an 85. I have checked the wiring one to the other and the circuit boards are the same except for the gas gage position and the tach (which I expect). The pig tail in the 85 has one open wire position #14. The Pig tail from the Tach gage set up is missing two wires in positions #14 & #15. Number 14 is the 3rd lug of the oil pressure gage (which is un-needed). Number 15 is the common between oil pressure, water temp, and fuel I am assuming it is their ground? Also I was given the pig tail for the tach it has a 3 prong connector that goes on the back of the tach that contains a black wire(ground) a brown wire (to the distributor) and a pink (12V hot) that I am assuming. However connected to the pink wire is another harness that I don't have a clue where it goes to or what it is for. It is about 32 inches long and has two connectors on it. One has 5 wires in it and the plug is in the shape of a bow tie. The other end has 4 wires in it and it is in the shape of a "T". Two wires side by side on the top like this --two vertically like this II. In each plug the wire colors are tan with a white strip, tan, light blue, light green. The bow tie shaped end has the additional pink.

These are my questions:

1) Does anyone have a wiring diagram specific to an 85 Cluster with Tach and gages that scan me a efile copy?

2) Does anyone have an 85 Truck apart that has a factory Tach that can shoot me some pictures?

3) Does anyone know if the output for the little fuel gauge is the same as the big one?

4) Can I just move the wire in the loom to the new position for the gas gage or do I even need to?

5) Can anyone shed some light on these questions?

I don't want the nickname Sparky.

Thanks in advance for any help you can give.