As JLeonard says: "I don't believe you have the pump that fails often."
The 210/220 HP 6BT5.9 uses a small Sherwood M71 pump (1-1/4") that SeaBoard does not offer (presumably because it does not fail like the 17000 series on the higher horsepower engines).
My first pump went 3253 hours before I rebuilt it and placed it in reserve. The second pump is now at 2900 hours. I get around 750 hours on the impellers, and I've put in new backing plates and cams, but this is all normal maintenance.
The tensioner doesn't seem to be a problem either as long as you don't change out the 65A alternator for a high output alternator. The first one went around 2000 hours before it started making a little noise, the second one was just replaced with 4198 hours after it started making a little noise.
CPL 0742, cruise 1600-1800 rpm, now over 6000 hours.