Offshoreonly.com - Rodoing Bunk boards

It is time to do some work on my trailer, so I am starting with the bunks. Currently have 4 bunks that are 2X6. Bottom ones are just under 16 feet long and the upper side ones are just over 11 feet long. I am going to move the bunks a little, as the dry storage forklift had trouble getting the the boat off and actually ripped one of the outer bunks off. Not a big deal, as was going to replace already and screws were all rusted (was already lose).

What I was thinking was moving the bottom bunks down about an inch and the upper bunks up about an inch (would give more room for the forklift). The metal mounts are 3 inches wide. I was also thinking of making the boards a little more narrow. Currently, the boards are 5.5 inches wide. How narrow can I go? Not sure if it even makes a difference. It is a 24 Pantera.