[66Sprint200]

Hey guys, I have a quick question. Well, about a week ago, 66aquagt posted about a trade between him and I. I gave him hubcaps, and he gave me a fog lamp wiring conversion kit. Here's where the question comes in. I am currently redoing (painting & rewiring) my engine bay, and even though I don't have the lamps or switch yet, I figured I would at least start getting it hooked up. Unfortunately, the fog lamp wiring kit doesn't have its instructions with it. I want to drill the 2 holes in the radiator support to put the grommets in for the wiring that goes to the lights, but I don't know what size they are. I looked online and found an article about putting fog lamps on your 65 or 66 Mustang by Mustangs Monthly, but that made me more confused. It said I am supposed to drill two 33/41 inch holes, but at the hardware store, I was nobody makes or carries that size. So, what size are the holes? Thanks, Michael.

[Calponycarsmike]

31/44 inch = 17.8954545 millimeters


But since that is not helpful this is a cool little tool Lenox MVB618 7-Hole Metric Vari-Bit (6mm to 18mm) at Arizona Tools

I would get the grommets and draw a template and just drill to fit, the MM artical does not even show the type of bit they they used, and I have never seen a 31/44 hole saw anywhere.

[Ivy66GT]

Forget your metric converters; Ford was definitely not metric in 1966. The holes for the factory fog light grommets on a '66 are 3/4" diameter. I think you will find a little ding in the sheet metal not far from each of the horn wires where the fog lamp holes should go.

The best tool for a clean hole would be a Greenlee chassis punch which uses a smaller hole for a through bolt which then draws the two halves of the punch together from opposite sides of the metal to make a perfectly round, flat and smooth hole.