<P> In 1980, the design of the block was changed from a cutout block, consistent with a 1940s style front - engined Indy 500 car, to a solid block . The tires were also changed from narrow, hard plastic, to wider "slicks ." </P> <P> In May 2005, the Boy Scouts of America registered Pinewood Derby as an official trademark . </P> <P> The Scout is given a block of wood made from pine, four plastic wheels, and four nails . The finished car must use all nine pieces, must not exceed a certain weight (usually five ounces (150 grams)), must not exceed a certain width (usually 2 - 3 / 4 inches (7 cm)) and length (usually 7 inches (17.8 cm)) and must fit on the track used by that particular scout pack . </P> <P> Blocks can be whittled with a hand knife, bandsaw, or Dremel carving tool for major shaping . Decals can be bought at scout shops or hobby shops . It is also possible to use standard model decals to replicate actual racing cars such as Richard Petty's 1970 Plymouth Superbird . The original style is based on open - wheel cars; however, fender or body kits are available, or wheels can simply be placed outboard of the body . </P>

What kind of wood is used for pinewood derby cars