underpinnings since 1961, the Panther chassis marked the first time the two model lines shared a common wheelbase (114.3 inches, downsized from 124 inches). Although reduced in size, the Grand Marquis would retain the basic suspension design of its predecessor, with a live rear axle suspension and double wishbone independent front suspension, with coil springs at all four wheels. In 1985, gas-charged shock absorbers were standardized for the model line, with load-leveling rear air suspension introduced as an option. The Grand Marquis was fitted with front vented disc brakes and rear drum brakes. For 1986, 15-inch wheels made their return as standard equipment (after having been an option since 1979). Powertrain As the Grand Marquis became a distinct model line for 1983, its powertrain underwent several revisions. The standard 4.2L V8 was discontinued, with a 130 hp fuel-injected 4.9L V8 (rounded up to 5.0L by Ford) becoming the sole engine offering. Shared with the Lincoln Town Car and LTD Crown Victoria, in 1986, the 5.0L V8 adopted multi-port fuel injection with a cast-aluminum upper intake manifold, increasing output to 150 hp. As an option, a 180 hp 5.8L V8 made its return for the Grand Marquis; shared with Ford police/fleet cars, the 5.8L V8 was the final carbureted engine sold in North America by Ford at the time of its 1991 discontinuation. Both the 5.0L and 5.8L V8 engines were paired with the four-speed AOD overdrive automatic transmission. Body The first-generation Grand Marquis was offered by Mercury solely as a sedan, in two-door and four-door configurations. For 1983 only, the Grand Marquis was offered as a station wagon (effectively a Colony Park without woodgrain trim); from 1984 onward, all full-size Mercury wagons were Colony Parks. While styled nearly identical to the LTD Crown Victoria, the first-generation Grand Marquis was three inches longer than its Ford counterpart; alongside the doors and front and rear windows, only the bumpers are externally shared between the two model lines. After the 1987 model year, the two-door Grand Marquis was discontinued; only 4,904 were produced. Exterior In contrast to the stainless-steel band surrounding the B-pillars of the LTD Crown Victoria, the Grand Marquis was offered with multiple vinyl roof configurations, sharing the B-pillar "coach lamps" of the Lincoln Town Car. Alongside the standard half-length vinyl roof, a full-length roof was offered; the LS offered an additional option of a "formal roof", configured with a "frenched"