I figure the grille is big enough as is. I think more intake, especially up there, would look excessive and detract from the appearance. I swear I have seen it done but don't know where. Maybe a competition vehicle, but it didn't make it look better.
They may have gone to the blunt, more truck-like (we know it was that), nose to accommodate the rapidly growing personal use 4wd and RV market. I mean '69 was first year for K/5, '70 4wd was available for the first time across the line-up, Suburbans had become much more comfortable & bigger, and campers were a huge market. Things had expanded well beyond the C/10 pickup.
I like them all in any form. But if I could only have a 4wd and a 2wd it's 4wd 69-72 and 2wd 67/68. I want the blunt on a tall 4wd (that should have a winch bumper on front) and sleek on a short 2wd. More utility on one and more style on the other, in it's general outline.
I'd really like to have an example of all. A 67/68 K-model is not wimpy looking and a 69-72 is no ugly duck
