500? 
a
You’d be surprised. They wear out quickly in racing applications because they’re constanly revving to 10,000 RPM. That won’t happen in road use. NASCAR enginges are really quite simple in many ways; they still use carburettors, for example.
However, racing engines use ultra-low viscosity oil, and NASCAR engines in particular are mostly iron, so they’ll corrode astonishingly quickly.
Oops.
That’s what I thought, every part of a racing engine is specifically designed to run 500 miles at 10,000 rpm … intake manifolds, piston shape, ring end gap, etc etc etc … one would get even less miles if they idled the thing too long at stop lights.
I remember (barely) the good ol’ days when a stock car was exactly that. They’d even inspect them to make sure there were no parts in them that the ordinary Joe couldn’t buy at his favorite dealer or parts store.
As I remember, the builder had to produce 150 cars before they could be allowed to run one in races. So you could just buy one off the assembly line.