Very interesting link.
Flat Erie:
"It always amuses me how many opinions there are on this topic.
Simplest & cheapest is the 7806 chip - they're cheap, maybe $0.15 each. One for each gauge except your voltmeter. Put a 60 ohm resistor (precision wire wound) in series with it - it's close enough.
The runtz are resistors and aren't as stable as the digital CVRs. The 'factory' 56-9?? Ford item is a chopper and while it will work, also isn't stable. Like many things, there is more than one way to skin a cat and your opinion of what is 'better' is just that...an opinion. It boils down to what you value most...cost, simplicity, accuracy, ease of installation, or???"
Seems like another topic where there are about as many points of view as there are posters!!!!