At this point with the trucks being higher from the factory you just about have to have a step or a ladder to reach any tool box. I have two tool boxes (both not being used), one a low profile as even with a long bed I did lay my fiver on the box and hit the cap with the corner of the box (high profile box). Was an old (2001) with a straight cap.
Yes I did 4 1/2 years active duty in The Corps (74-78) and then 30 years in the Air Force Reserve (80-2010). Was good to me. Thank you for your service and to your son "Semper Fi"