If you're replacing the 3 thermal instruments with some aftermarket brand, you'll need to know if those are designed for reduced voltage or 12 volts. I'll guess that majority of those that operate with the OEM 80-10 senders do require reduced voltage.
None of this is relative to any tachometer, OEM or aftermarket. Instrument voltage regulators are relative to fuel, oil, temp, / thermal instruments only.
Forgive me if I've misunderstood your post, whats replacing what.[/QUOTE
I am going to replace them with the Rallye gauge set from Classic Industries which includes temp,gas,alternator,and
