I'm happy to share my experiences. My 94 had alot of deferred maintenance by the previous owner. Plugs are very hard to get at, and like the SHO it is a more expensive car to maintain if your taking it to shops. Having taken care of those issues my biggest issue was cooling. the radiator is rather small because the intercooler takes up alot of space. Ford also chose to run very high cooling system temps (220 low speed on and 228 high speed on for 94-95, slightly lower in the 89-93) with a narrow window before being too hot which head gaskets are an issue. If any of the air scoopes and such under the front bumper are missing and you have any cooling issues to start with you'll have cooling issues. Having fixed the air damn, and shrouds underneath, as well as having a 180 thermostat and very important chip to revise fan on and off temps I now have no cooling issues. In 111 desert heat the car will stay at or under 200. Before it was constantly hitting 230.If you do not revise the fan temps the car will still have issues even with a lower temp thermostat.
Suspensions also are different, the ball joints in the front are prone to wear as they are undersized for weight of the bird. Get good moog parts, as I had a new ball joint fail with about 5k miles on me, while on the fwy. The adjustable shocks are available from tokico to keep the auto ride functional.
After getting the bugs from lack of maintenance worked out, it's been a fun reliable car. Driven it from socal to texas and back. It may be heavy but it is very quick, and may seem soft and slightly float in the soft suspension setting, but it is a blast in the mountains in firm ride, it feels like a BMW (6 series was it's design target in 89). Will easily break the rear end loose and wet traction be very careful when accelerating. Highway passing is very easy, almost instant.
