Why do 99-02 Chevy Silverados have different grille styles?

[Friggin Mustard Tiger]

Hello everybody. I am wondering why 1999-2002 Chevy Silverados have different grilles. Some have mesh grilles that are sort of diamond shaped and some consist of strait lines forming rectangles. Idk the terminology, sorry. I haven’t been able to find any information on the internet about this and it seems to have nothing to do with trim, size, or year. If anybody could answer this I would appreciate it. Thanks

[davester]

Just different designs, as it's relatively cheap to alter the grille for a different trim levels or to differentiate one year from another.  Everybody does it.

[MORSNO]

Different trim levels came with different grills, GM has always done this.