I have those for my project too. THey along with most, will allow for you to stick the signal stem thru the headlight mount hole, thread it into the nut that holds the headlight on, has the ground wire on it. YOu'll have to tighten the stem first with the lamp loose on the stem. THe chance of the lamp being in the position you want when the stem is tight is remote. Stock lamps or any with a 10mm stem.
I consiodered drilling a hole but those ears are really nice and I didn't want to mess them up. I had mine chromed, even though they came with a high polish on them, they were duller than my chrome headlight shell.