96-97 E320's have the same 3.2 liter M014 engine as in the 93 300E / 94-95 E320, and all the way until 1999 in W140 chasis S320's.
The 96-97's have OBD-II, not OBD-I like 93-95's.
The wiring harness is not a problem. The wiring harnesses were bad from 93-95.
The only thing I can think of is that the head gasket may develop a slight oil leak over time, at the right rear corner of the head gasket (the passenger side), and at the front 'C-shaped' area of the head where it seals with the timing chain cover.
The M104 engines are really smooth, quiet, and powerful. I think you'll love it.
2001 E430, Bourdeaux Red, Oyster interior.
1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".