I rewired my shoebox a while back with a painless kit and wanted to retain the stock gauges.An electritian buddy got me some of these ceramic reducers and they dont work--NONE of them.I remember seeing a post of some east coaster that has a website that sells something simmilar that really works. Thanks ---FEDER
I went back and re-read your post. If all you need to drop voltage for is stock gauges, use a ford "voltage limiter" for gauges only. Ford used them from 1956 to 1967-68 when they went to a printed circuit on the back of the dash's.. They are still available from Ford or even Napa. I get mine from the back side of 12 volt early ford insturment clusters at the junk yard. They're a little square box with spade connectors going in and out. Held on with one screw. Don't try to use them for anything other than insturments. They'll make smoke if ya do....
I use Borg Warner P/N VRC 603. Its a guage cluster voltage reducer used on 12v Fords from the 50's thru 70's. It ties in to the power feed to the Gas, oil & temp guages. NOT the wire that goes to the sending units. You only need one as these guages get power from one wire jumped to each guage. Hope this helps, Billy