Hard to imagine what "power surge" there is going to be to stock gauges that draw less than an amp each??
I used a NAPA IR-1 for a couple of years, but I could watch the gauges cycle up and down under steady conditions as the thermal element pulsed. Their newer ones seem to have been cheapened up considerably. So I bought one of these, and it is excellent:
http://www.ebay.com/itm/Ford-Instrum...item4175acd131