need gauge cluster wiring diagrams

[Jonboy]

I am getting ready to Frankenstein a tach cluster for my '74, and need to see if anyone has a diagram of the gauge cluster for a '74 and 76-77. I am going to put a voltage gauge in my '73-4 tach cluster, and repin the plug. Just need to see what is where. I think I have a '77 cluster in there already, it has a voltage gauge and mechanical oil pressure. I am almost sure it is the one out of my old '77 Blazer, but don't remember for sure. Thanks in advance, if anyone has them....