7/16" or 12mm lugs for a '72 Malibu?? & What lugs for Foose Legends??

7/16" or 12mm lugs for a '72 Malibu?? & What lugs for Foose Legends??

I was spec'd (from five or six sources) 12mm lug nuts for my Malibu. Problem is, after doing a little research, I'm seeing 7/16". Apparently things didn't switch over to Metric until the mid-late 70's. The pimply faced kid at AutoZone wouldn't know that. He looks up Chevy Malibu and sees 12mm so that's what he sells you. I was using the 12mm (because that's what I saw on a lot of different fitment charts), and lo and behold- I made a right and my wheel went left. It turns out that a 12mm bolt is almost a full mm larger than the 7/16" (11.11mm). That's close enough that the lugs will thread properly (seemingly) but loose enough that a 4000 lb. car would jar them loose after a few bumps in a highway. Rocket science, I know.

SO, which is it? Is anybody else using Foose Legends on a 70' something Chevelle?? What lug size are you using?? Also, what lug specifically, because the holes for the lug nuts in those wheels are so narrow that I can't even get a standard tire iron in them. I'm about to go get a Honda Civic with a propeller on the back and be done with the whole thing, man. I'm starting to feel like this car doesn't like me very much.