I heard that the gauges in my 55 would work on 12 volts but someone did not know what they were saying as the temp gauge never worked right after having 12 volts run through it,it starts out about 1/3 up and them pegs all the way over to hot but before I hooked up the gas gauge I installed a IVR in line to the gauges and the gas gauge works fine so I hope I only fried the temp gauge.  I picked up a NOS temp gauge off ebay cheap and as soon as it comes in I wil install it and see if I have a correct reading temp gauge again.

Butchering up everything I can get my hands on in Dayton Ohio

I heard some where that you should install a 6 volt voltage dash reg.ford used them inthe 60,s on their 12 volt system because the gages worked on 6 volts that way it wouldn,t burn them out and they worked fine  just something I heard  Shakey Pete maybe somebody else has more info also maybe they used them in 56???

Junk yard ......I have always heard that  the 56 ford was the only year that 12 volt gauges were used ,  your sending unit maybe a 57 in which case  have you will have to use to use  a reducer  , forget what they are called , but original on the 57   ...But on a 56 the gauge runs on 12 volt .....have one in my garage now ,  works good..!!!...............Sam                              Florida  West  Coast

56 victoria

Junk yard Jeff,    Just reread  your  question didnt see you have a 55 ...You will have to use 6 volt sending units  or  if you have converted to 12 volts ,   reduce   every gauge to six volts..............   Sam

56 victoria

You need to use a voltage drop for the gauges.Most of the specialty suppliers like Macs and Tee-Bird sell one or you can use the ones used on the 60"s Fords like the Mustang-Falcon.Hard to find though.

  

I am using a IVR from a 60s truck and I do have a original sending unit,I am glad I had the gas gauge disconnected when I shot 12 volt through them.  The gas gauge works fine so I hope I only fried the temp gauge and I also did not have the original sending unit in it when I done it,I have a 351-W in it now and was using a late model sending unit but learned the need the original so I found one.  I bought a reproduction sending unit and it actually started out half way up so the used one went back in so as soon as the gauge arrives I will put it in and see if I have a properly working gauge.

Butchering up everything I can get my hands on in Dayton Ohio