The '92-96 wiper valance will NOT fit older trucks because of the difference in hood lines, but the '87-91 will fit '80-86, and the pinholes keep out leaves that normally fall through the slots in the older valance.
They DON'T stop the leaves that slide between the w/s & the trim/valance, so other mods are required to keep the cowl clean. For more info, see:

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