The XJ Cherokee was first introduced in the fall of 1983 (1984 model year) in 2 and 4 door configurations, 2 and 4 wheel drive with either a 2. 5L 4cyl, 2. 8L V6 or a 2. 1L Renault turbodiesel.
The listed shipping weight for a 1987 4cyl 5 speed 4 door is 2983 lbs and for an 87 6 cyl 5 speed 4 door it's 3126.
The ZJ Grand Cherokee was an all new platform introduced in 1993 to replace the SJ Grand Wagoneer that was discontinued after 1992. The SJ Cherokee was discontinued after 1982 to make way for the XJ Cherokee.
FYI, the 2 door and 4 door XJ Cherokee have the exact same wheelbase (101. 4")
Later,
Joe H