I don't know if this question was answered or not but I recently put those headlight bezels on my 73 (I like the full chrome front). The only difference is the lower grill trim, as far as mounting locations I found them to be in all the same spots.
I removed all the necessary components from a 1979 C10 which I believe was the first year for those style bezels. To my knowledge they were on the 1980 trucks too but only on the lower trim models.
