Fried gauges?

The first test is quick and easy. Disconnect the sender wires and connect jumper wires from the connectors to a good ground. Sit in the drivers seat and turn the ignition switch to the on position. If the gauges start to move, immediately turn the key back off. You now know the gauges work....they may not be accurate, but, at least they work. If the gauges don't move, it can be fried gauges, bad connections, wiring problem, etc. If one works and not the other, the IVR works, but, you still may have a combination of the other problems mentioned above. Getting another used cluster with good gauges shouldn't be all that hard to find. The same gauges (with some minor variations) were used from '72-6 on all A-bodies.