As in the Pantera, Ford 5.7 liter (351 cu. in.) V-8 was called upon and rated at 300 horsepower (DIN). A Ford 3-speed C-6 automatic transmission was initially the only offering, however approximately 17 cars were built featuring a ZF 5-speed manual transmission. The Longchamp employed the same powertrain, brakes and suspension as the Deauville, fully independent, with inboard brakes and dual shock absorbers at the rear. These combine to give the car an exceptionally comfortable yet stable ride, and confident handling. Power rack-and-pinion steering, and 4-wheel power disc brakes were standard.
The coupe interior was fully trimmed in leather, including the seats, door panels, dash fascia and console areas. Power windows and fuel instrumentation were also included, as were dual gas tanks and fuel pumps. Beginning in 1979, an updated interior and exterior package included a more integrated bumper design, revisions to the heating and air conditioning controls, and the introduction of the Longchamp GTS model. About a third of total production was the Series II cars.
The Longchamp GTS is similar in concept to the Pantera GTS, that being a bolder-looking and better-handling version of the original model. The body was upgraded with flared fenders and the standard 7" x 15" magnesium wheels were replaced by 8" x 15" and 10" x 15" (front and rear, respectively) Campagnolo units (from the Pantera GTS) wearing Pirelli P7 V rated tires. It is estimated that up to 60 GTS models were built.
In 1982 the GTSE model was introduced with running boards connecting the flares similar to the Pantera GT5 and the bumpers were integrated into the body. About 10 GTSE models were built.
Approximately 409 Longchamps were built during the car’s production life. Carrozerria Pavesi of Milan was also called upon to factory convert 16 Longchamps into handsome convertibles. A very few of those were also GTS models, making the Longchamp GTS Spdyer an exceptionally rare and desirable machine. About 15 RHD cars were built. The Longchamp was never officially imported into the US with about 25 imported by owners.
DeTomaso bought the Maserati company in 1976 and to quickly bring a new model to market used the Longchamp with some new grill, engine/transmission and bumpers calling it the Kyalami. It used the same suspension, brakes, steering and differential as the Longchamp, which was based on a shortened Deauville. 200 cars were sold from 1976 to 1983 with a manual transmission available.