Here is a stupid question for ya. What is the name of the black hard plastic piece on the underside of a front bumper?

Also, does anyone have one for a 1998 F-150 they want to sale?

 

I think it is the front valance.

 

I call it an air dam, maybe mistakenly.

The only reason is when I got the replacement for the stock one, PIAA calls it an air dam. Right or wrong, that is what I have called it in the past.

If you search here on the Forum, you should at least include the name air dam, to make sure you get all the options, as I have also seen others call it that.

Front Valence might actually be the correct name for it though...

 

If you need one, now would be a good time to get an aftermarket one that is much nicer. A lot of people have swapped the original out for a color-keyed aftermarket valance maybe with lights.

If you do get a nice one, whatever you did that caused you to need one, well...
...don't do that anymore.

I'm partial to these:
http://www.truckmasterdesigns.com/