My 78......... Or at least I thought so.

[78chev]

After combing through various pics on this board I think I might have a 79, not a 78.
My title says that it is a 78 but it has the grill/bezel setup that surrounds all of the lights including the turn signals.
I can't find a build date anywhere on the truck and the only distinction that I've noticed between 78 & 79 is the grill.
Is there any other way to tell?