The term valance, air dam, and baffle are being used interchangeably so what follows pertains to all 3.
First a reply to sch911. Why do all your (FCA) trucks have them if they serve no purpose?
Bob, your 95 most certainly had a lower deflector on the front bumper from the factory. If it's a 4x4 it had cutouts for the tow hooks. It most certainly has an effect on both cooling and aero. Aero=mpg. I think most people that know what they are talking about will agree that the lower you are the more cleaner you are from an aero standpoint. This means your RV as well and it's why towing nose high will impact your mileage.
Some vehicles also have a baffle right at the bottom of the radiator core support to further help in cooling but they are more common on passenger cars that are already low enough bumper wise.
If it was my truck I would put one back on. Even Amazon sells them, along with several other AM companies. The GM ones are a little pricey in comparison.