IVR pulse at 4 volts gauges read low

Working out those minor details. 69 Barracuda

My IVR pulse is only about 4vdc, gas, temp and oil pressure gauges are all working but all seem to read lower than expected. Ohm readings on sensors seem to be ok.

Before I yank the cluster back out and do the solid state upgrade looking for some opinions on the voltage output. Would this lower voltage cause the lower readings and just be corrected by getting the correct 5v signal, or would it be wise to replace all the gauges while the cluster is out?

I took voltage measurements with a quality analog meter from the three sensor wires. Battery voltage at 1000 rpm reads 14v. All wiring harnesses are new M&H pieces.