I have tested all the gauges and they all work as they should with exception of the gas gauge. I believe it needs the air core motor replaced. I don't have one or I would replace it. I did test the circuit board for fuel gauge signal and it does read properly. The odometer works and the tripo meter works and resets. The lens is pitted and scuffed, I tried to get some photos of it the best I could. A replacement lens can be bought from LMC truck for cheap. 

This is the cluster that can be swapped into 88-91 GM full size trucks with the "moonie" style gauges if you want a factory cluster with tachometer. A few wires in the dash connecter need to be moved and a wire added for the tach depending on the year of your truck (88-90 usually need 4 wires moved in the cluster plug, 91 is usually plug and play). I can provide you with another pin for the tach and a list of the wires that need to be moved in the connecter. I have done this swap on my 1990 GMC Sierra. It was fairly simple and straightforward.