With only a few exceptions, all U.S. cars used either USS or USC (USS --U.S. standard or U.S. Course) same thing, or SAE which is the "standard" fine thread
Some exceptions: Intercrashional Korn Binder Shouts used hydraulic clutch components from England and used "British Girling" brake fluid and I assume were metric pieces.
Some "fake imports" such as the old Mazda built Ford Courier, all Jap and all metric Some of the old early Postal vans used Brit stuff, Austiin I think. Buick Opel, etc. I don't remember for sure Pinto, but damn sure Chevy Luv and S-10
And Holley screws. Holley does / did not use standard machine screws, like 10-24 or 10-32, or 6-32, etc etc. They used weird threads which would more closely resemble something a gunsmith would see
Under the "wish I'd saved it" department, one day a young kid I knew, worked at the local Chrysler dealer, had been inserting service bulletins into the cataloges. He showed me one, it detailed the affected models and years, etc, and said basically that the steering wheel nut was metric
IN OTHER WORDS THE NUT BEHIND THE WHEEL LOL
