It will be wired like any other gauge .you will need to reduce the voltage to 6 volt and match the fuel sending unit , reverse the amp meter connections if you are running negative ground .

I don't think its that complex .... depends on the person.... but it will take some dicking around to make the originals work. I see his point . He has to answer or justify the hours he puts into it.  At the end of the day when an old set of mechanical gauges cost the same as a new set of programable digitals its hard to justify. Time is money but most of us don't count time. here is the voltage reducer

http://www.macsautoparts.com/ford_truck_late/gauge-voltage-reducer-4-amp-capability.html

i think the standard sending unit was 73-10 OHM so you will have to make that work with whatever tank you use

The amp gauge is iffy and you would more then likely be better off swapping it out with a volt meter

How close is the water temp and oil pressure for the engine you are using to the original flat head?

Just saying all this takes time as opposed to picking the parameters you want and hitting enter. One costs up front and the other in labour .