a standard spark plug should last 10-20K KM...those better/performance type should last 30-50KM....
Spark plug is wear and tear part...
Also life span of spark plug depend on your engine condition...if your engine makan engine oil / wrong tuning then your spark plug will wear out faster.
I plan to drop one of those engine into my new project. Which engine perform better? Half-cut cost? Some pomen told me SR20 NEO is better than a Honda's. It is true?
By the way I intent to fit it into my Citroen ZX...