Designed by Lotus Engineering for General Motors, the LT-5 was an all-aluminum 5.7 liter small-block V8 featuring 32-valve dual overhead cam heads; it generated 375 hp. For the 1993 model year, horsepower was bumped to 405 with cam-timing and engine-porting changes. The LT-5 became the most celebrated Corvette engine of all time, accumulating records along the way. In 1991, a slightly modified ZR-1, with a “bone stock” LT-5, broke three world endurance records at the Firestone test track in Fort Stockton, Texas. A team of drivers headed by Tommy Morrison broke the 24-hour endurance mark set in 1940 by almost 15 miles per hour, traveling 4,221.26 miles at an average speed of 175.885 mph. Two years later, a MerCruiser-branded ZR-1 took the checkered flag in the 24-hour World Challenge race in Mosport, Canada, with another ZR-1 finishing second. Production of the LT-5 ended in 1994.