There are actually three versions of the Taurus SHO. My family has all 3... There is the 1988-1991, 1992-1995, and 1995-2001 (last year for the SHO was 1999)
In 1988, the SHO was called an "MT-5" and sported a 3.0 liter V6, rated at 200 horses. The first year for the SHO was 1989, and it sported a Yamaha 3.0 liter V6, rated at 220 horsepower. This 220 horsepower V6 was standrd fare in the SHO until 1996, when Ford SVT dropped a 3.4 liter V8 producidng 235 horsepower into the Taurus. In all years of the SHO except 1988, 1989, 1990, and 1991, a manual transmission was standard with an optional automatic overdrive transmission.
These cars are wonderful, spirited vehicles. It's a lot of fun to race f-body cars and keep up with them in a 4 door car. The 3.4 liter V8 is conservatively rated at 235 horsepower for safety regulations but it's considerably more powerful than that.
But yeah, manintenance is very bad.. I don't know why, perhaps a Taurus isn't meant for high performance. Ford beefed up the suspension for the SHO model line but it doesn't seem to be enough. My brother's, for instance, eats tie rods and cv shafts like no one's business. Alternators, starters, a/c compressors... They all seem to have a short life expectancy in the SHO.
If he can get it cheap, and if he's mechanically inclined, then he should get it. Until 1994, they were relatively easy to work on. However, AFTER 1994, with the advent of the V8 in that tiny engine bay... Well, lets put it this way. My brother has to loosen motor mounts to change spark plugs.