If they were higher (over the spec), i'd be more concerned i.e. like greater than 12K. Being on the low side is not likely to be an issue although those plugs may show a different hue (color) on the porcelain if examined.
You might for kicks and grins measure the spark plugs themselves. They also seem to have some variability. Mine were all on the low side. Spec says 5K, measure 3.8k from the plugs electrode to the connector at the plug end.
The main thing is to make sure the caps tighten on to the wire securely and resist rotation. Also keep the plugs gap UNDER spec and you should be good. If using fancy plugs take care as not damage them should adjustment be required. ((Do check the gap and do not assume its correct for our application))
Good luck!
You might for kicks and grins measure the spark plugs themselves. They also seem to have some variability. Mine were all on the low side. Spec says 5K, measure 3.8k from the plugs electrode to the connector at the plug end.
The main thing is to make sure the caps tighten on to the wire securely and resist rotation. Also keep the plugs gap UNDER spec and you should be good. If using fancy plugs take care as not damage them should adjustment be required. ((Do check the gap and do not assume its correct for our application))
Good luck!