as was told to me , by nhra tech, the two year limit is what military has on their belts in jet fighters, i use to work in avaition, long time ago, we had 20 year old stearman biplanes with same harness as when built in 1944, this was in 1964, never replaced any of them, airliners do not replace any belts . car belts are never replaced either. just food for thought.
