A pallet of sod will put a supercrew pretty close to the bumpstops, half a pallet sits about an inch below level.

 

If you are anywhere near your bumpstops you are overloaded.
They are there to prevent overtravel of the suspension. If your suspension can not absorb bumps because you are loaded too heavy you can easily loose control on even a small bump as there will be no suspension give.

 

alright good to know. i was about to go pick up a pallet using my bed but i guess ill have to break it up now

 

I dissagree. I've had lots of weight in my bed and it hasn't caused any problems with control over large bumps at all. If your tires aren't rated for the load then you may have problems with control being the sidewalls are not made for large amounts of weight on them. If you have load E tires then everything will be just fine. The rubber bumpers are there to help the truck when it has weight on it and it prevents harsh hits when going over large bumps. They also prevent damage to shock absorbers from bottoming out. As long as you don't go overboard and only go a short distance then there shouldn't be any problem.