I have the rear fenders removed but the bed bolts have me stymied. They are the stock factory steel bolts with the large head inside the bed. I have been spraying them with a knocker-loss for a couple weeks, but they don't budge. They are so tight they won't rotate with vice grips and I've tried taping them while supporting the bed sheet metal with a pipe just larger then the bolt's mushroom head. What is the secret?

 

So, you're trying to remove them? Why?

 

These bolts have 4 small spot welds around the bolt shaft that holds them in place. I always remove these bolts because it makes it much easier to prep/paint the bedsides. I have found that the best way to remove the bolts is to clamp a vise grip onto the bolt and rock it up and down until the welds break. Don't get too carried away or you will bend the metal on the bedside, just start easy and work your way into it until it breaks free.

 

I just ran a die on them and let it go.
Worked OK
Couldn't get first one off so quit.

 

A couple of the bolts twisted off in the threads during disassembly. All will be replaced with new.

CharlieLED - I never would have guessed they were welded, but it makes sense considering how tight they are. I'll try your technique today. Thanks!

Also had to remove the front bed panel (rust all along lower edge). It was held with 4 rivets and 2 small bolts on each side. After removing them the panel was still tight: Henry also added two spot welds mixed in with the rivets!