Matt,
I'm not a body man, nor do I pretend to know much about the process... However,
Having owned 3 46 sedans, and a couple of AD's my opinion is, it would take a significant amount of work.
The AD truck grills are for the most part a straight rectangular shape. The auto grills your asking about have rounded top corners and grill bars that extend out beyond the inside edge of the fenders/grill opening.
By the way, while I believe the 46 and 47 auto grills are either very close in size and design, or actually interchangable, they don't look the same.
In the automobile applications, 42 and 46 both had a one year specific grill design. 47 and 48 were virtually the same grill, with the difference, (I believe) of a center T-Bar being added in 48.
With all of that said, you know how it goes... With enough time and money, anything can be accomplished. Good Luck.
Oh by the way, Welcome to the Bolt!
