simple connections 68 burban

[vectorit]

I am just stuck on some simple connections that I forgot how they originally went in...

1. The vacuum gauge on the gauge panel. How did that hose get routed, and what is the best type of tubing and fittings to use to ensure an air tight connection.
2. The fuel tank gauge wires. Originally mine were all butchered up, and was a huge rats nest. Now, being that I am using all new wire harnesses I am confused. On the burbn' was there a wire that ran from the sending unit all the way to the fuse block? Or was it wired into the rear tail light harness? I just ran the new rear wire harness, and after all the lights are connected I have an extra plug. Is this plug intended only for the license plate light, or is it shared with the plate light and the sending unit? The wire diagrams suck, and the resto shops don't sell this last little bit of harness.
3. The amperes gauge on the gauge panel. I can't seem to figure out how that sucker got wired... There are only two screw post type connectors on the back. Again my wire diagrams from all my collection of 68 truck books don't show anything helpfull.

Any input or better yet pictures would be great, since my ADD don't work to well when it comes to reading wire diagrams!

Thanks!