Sportsman, Dodge Tradesman, Dodge Van, at first; they later changed to Ram Van, Ram Wagon, and, briefly. There was also a Kary Van extended height model. The cargo and passenger vans used the same frame and powerplants (both 6- and V8 engines), but the passenger vans had seats for up to 15 passengers (on the extended length, long-wheelbase Maxivans), dual air-conditioning systems (in later years), and large windows on both sides. The 15-passenger vans are today commonly used by military, commuters, church groups, scouts, urban camping, and some corporations. Throughout their run, two wheelbases were used: and , with an extended-length version based on the longer wheelbase. Engines ranged from the 198 in³ Slant Six (available only in 1970–71), to the 440 in³ V8 (only briefly available in the late 1970s), with factory compressed-natural-gas 318 in³ (5.2 L) engines available from around 1995 onwards, to fleet buyers only. A popular Kary Van (basically a factory-built cube van, instead of upfitted by an aftermarket company), which extended the cargo area height to , was added in 1972. A sliding door was made optional in 1974; that same year, the original stamped aluminum grille was also replaced with a molded plastic part. A one-piece rear door and hard-service interior were made optional in 1975. For many years, Dodge was the sales leader for vans, including conversions for tradespeople, ambulances, school buses, and campers, working with numerous upfitters to provide alternatives for customers. However, in 1979, the RV market crashed, and Dodge stopped making RV chassis; their van sales also dropped roughly in half. After that, upgrades to the "B-vans" came more slowly, especially as the vans' utility was in some ways duplicated by the company's own popular Plymouth Voyager and Dodge Caravan minivans. In 1988, a 239 in³ (3.9 L) V6 originally developed for the Dodge Dakota mid-size pickup replaced the 225 in³ (3.7 L) Slant Six, and throttle body injection was given to the 318 V8. The 360 in³ (5.9 L) V8 gaining fuel injection and a roller camshaft in 1989. In 1990, rear wheel antilock brakes were made optional, along with a heavy-duty four-speed automatic transmission. In 1992, the V6 and 5.2L V8 engines were fitted with sequential multiple-port fuel injection (SMPI) and a "barrel" / "kegger"-type intake manifold, which boosted power dramatically, and the outboard positions of the rear seat gained three-point belts. In the same year, compressed natural