Measurement - box to cab

[59chev]

Can someone do a quick measurement for me. I just got my shortbed mounted up and need to verify how much of a gap there should be between the front of the box and the cab at the top of the front bed panel in the center.

It almost looks to me like I need to go another 1/4" forward but I want to check before I trim anymore off the rear of the frame rails.

Thanks..