Not visible in the picture (but as the bottom of the grille is visibly different I would guess they have designed the two format grilles), so they could just describe the grille mesh shape: square or diamond.
I did not realise the difference in the lights. Excellent.
The grilles are different, the Chevy one is diamond shaped, whereas the Ford one is a square mesh.
Actually there are several configurations of the headlights, so we wanted something which is more common.
Also, the windows can be very different too!
The way we had designed the cabs, you can actually "saw" off the rooftop, window frames, and portion of the cab back panel to make the cab an open-top vehicle too!