The Real Nascar car

The cars are high-powered, low-tech hot rods with a roll cage chassis and thin sheet metal covering, and are powered by carbureted engines with 4 speed manual transmissions. The engines are limited to 355 cubic inches (5.8 L), with cast iron blocks, one camshaft and a pushrod valvetrain. However, significant engine development has allowed these engines to reach exceedingly high levels of power with essentially 1950s technology.
Source: nascar-races.com