4cyl with 2 exhausts is gay, and purely for aesthetic reasons. A car of that age (late80's early 90's) wouldn't have had 2 on a 4pot, its more of a recent thing to do...
The cars were better (except for graphics) in the early stages. XFG was more powerful, XRT had 2 exhausts, FXO had wing and bodykit and then there was the mighty LX8 for some time.
But no way I would switch the current patch to some old one