Actually it's not that bad anymore, as it once was.
You can now get a "H-license plate" (historic vehicle) if the car is older than 30 years, in decent shape and if it is not too much modified.
After that you are exempt from a lot of rules that apply to junger/modern cars.
Then you have to pass safety inspection every 2 years (no emission test anymore) and that's pretty much it.
With a US pre war ride you have plenty of leeway anyway, cause the inspection guys usually have no idea what they are looking at - no way they could tell a 216 from a 261, or that I have a truck rear end. As long as it looks halfway plausible, Im good.
And of course you need insurance and pay vehicle tax.
yeah, that's frequently a minor blessing (having clueless inspectors)
who in many cases realize your unlikely to use the car a daily transportation,
so they are less inclined to be strict on verifying every minor component, function and authenticity during an inspection.