Installing an in-bed tool box

I would like to install an in-bed tool box permanently. My question is has anyone had problems with the composite bed cracking or failing due to something being bolted in it. I figured on using 4 bolts with large washers to distribute the loads over a wider area, but I am wondering if I should do something else. The truck spends a lot of time on logging roads (10 - 40 miles / day) due to my job, and I am worried that the constant vibration will damage the bed. Any ideas on this would be appreciated. Thanks.

 

Bump.

 

I've been wondering the same thing

 

Went ahead and installed it today. I will let you know if I have any issues. I used 1 1/2" fender washers along with putting the bolts next to where they reinforced underneath the bed.