According to the '94 "final version" of the MPC there were two grilles that were introduced in 1980 - chrome and black. But the chrome grille was used in both '80 and '81 while the black grille was replaced in '81 by the E1TZ version.
However, notice that the dark argent grille has an E1 prefix on it. So it is possible there was an E0 dark argent grille and it, too, was replaced.
What color is your grille? And pics would certainly help.
Gary, AKA "Gary fellow":
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Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI