The Chevrolet K5 Blazer is a full-size sport-utility vehicle that was built by General Motors. GM's smallest full-size SUV, it is part of the Chevrolet C/K truck family. Introduced to the Chevrolet line for the 1969 model year, the K5 Blazer was replaced for 1995 by the Chevrolet Tahoe. The third generation was simply called "Chevrolet Blazer", without the K5 name. In 1970, GMC introduced its own model of the truck, called the Jimmy, which was discontinued in 1991 and replaced by the Yukon. The "Jimmy" name was chosen to reflect how GM may sound in a similar manner to how Jeep was thought to be a pronunciation of GP in the competing market. Both were short-wheelbase trucks and available with either rear- or four-wheel drive. The K5 Blazer and Jimmy had "full convertible" removable tops until 1975. For 1976, GM introduced a half-cab design that was less prone to leaks and slightly safer in a roll-over. These half cabs had the convertible top begin a few inches behind the driver/passenger doors and run back to the tailgate. The Blazer's long-wheelbase relative, with an integrated rear body and doors for second row passengers, is called the Chevrolet Suburban. 1969–1972 The original K5 Blazer was built on the K10 pickup truck platform with a wheelbase shortened to , designed and marketed to compete with the International Harvester Scout (which had been introduced in 1960 for the 1961 model year) and the Ford Bronco (1965/66) utility vehicles. The Scout and Bronco were originally aimed at the Jeep CJ series and consequently all three vehicles were much smaller than the K5 Blazer. Because the Blazer was developed from a shortened pickup truck, this innovation both increased interior space and lowered the cost of production by using a shared platform. The Blazer quickly became popular. For the first time, it married the off-road capabilities of competing utility vehicles with "luxury" features like air conditioning and automatic transmissions that routinely were available on pickup trucks. By 1970, the Blazer was already outselling both of its older rivals. Ford, Dodge, and even Jeep would counter with similar shortened full-size pickups, including the Dodge Ramcharger and Jeep Cherokee, both introduced in 1974, and the revised Ford Bronco (1978). For its first model year (1969), the K5 Blazer was available with part-time four-wheel drive only. As an option, a removable hardtop or a soft convertible-top could be specified;