The popularity and performance of muscle cars grew in the early 1960s, as Mopar (Dodge, Plymouth, and Chrysler) and Ford battled for supremacy in drag racing. The 1961 Chevrolet Impala offered an SS package for $53. 80, which consisted of a 409 cu in (6. 7 L) V8 engine producing 425 hp (317 kW) and upgraded brakes, tires and suspension. The 1962 Dodge Dart 413 (nicknamed Max Wedge) had a 413 cu in (6. 8 L) V8 which produced 420 hp (313 kW) and could cover the quarter mile in under 13 seconds. In 1963, two hundred Ford Galaxie "R-code" cars were factory built specifically for drag racing, resulting in a full-size car which could cover the quarter mile in a little over 12 seconds. Upgrades included fiberglass panels, aluminum bumpers, traction bars and a 427 cu in (7. 0 L) racing engine conservatively rated at 425 hp (317 kW). The road legal version of the Galaxie 427 used the "Q-code" engine which produced 410 hp (306 kW). The following year, Ford installed 427 engine in the smaller and lighter Fairlane body, creating the Ford Thunderbolt. The Thunderbolt included several weight-saving measures (including acrylic windows and fibreglass/aluminium body panels and bumpers) and a stock Thunderbolt could cover the quarter-mile in 11. 76 seconds. The Thunderbolt was technically road legal, however it was considered unsuitable for "for driving to and from the (drag)strip, let alone on the street in everyday use". A total of 111 Thunderbolts were built.