if another coil pack has gone bad, I would try and convince the customer to go for the full set, as this is most likely a high hour truck that had not had the spark plugs changed for very many hours.
These crank and cam sensors, are they new or from a good running k21-k25 motor? these days, I would want to test them in a truck that ran before I trusted them for a 120 mile each way drive. just lately, I have seen a truck that ran OK but had a crank sensor that set a cam sensor error about 1 time in every 20 or 30 starts. it did not have any effect on the operation and it became a historical code the next start cycle.