normaly id say your right, however, ive seen alot of 77/78 trucks with the 72-76/79-80 lower vallence added, now weather at any time the factory added it i cant even be sure any more as ive come across some that have all the correct grill alignment holes..to which makes me question if ma mopar atleast rolled a few out that way...as we ALL know.."never say never when it comes to ma"
also on the side markers the guy down south of me has atleast 1 in clear, and ive runn across atleast 1 truck in the past that had them..now again i dont know if this may have been a euro thing, canadian thing or just some aftermarket thing thats long since dead, but he had atleast 1 i saw in his tubs of them, hell it even could have been a full on custom job for all i know
...but..
such an item exists so it bears asking since said truck is not stateside..and may have been required to be retrofitted with god knows what to get into the country