Which lug nuts for these wheels?

[Anthony Fremont]

I just scored these on CL:
http://houston.craigslist.org/pts/757665101.html (the mags, not the rallyish type wheel)
The guy just dropped them off and the tires have tons of tread, but they're a little taller than I'd like. I don't know for sure yet, but I'm thinking that these have to be 8" wheels due to the tire width. The wheels are in pretty good shape, but one has a mark where something rubbed thru the clearcoat. Not exactly my idea of "LIKE NEW", but for the money......

The lug holes in the wheels are pretty big compared to my studs. The lug nuts that came with the wheels just slide over my studs and I'm assuming they are metric anyway. The holes are coved out for an acorn type nut. Can I just use my stock lug nuts or do I need to do something special here? It's no fun having wheels come off at 60MPH, don't ask me how I know....