I bought an aluminum dry box off ebay. I am not sure if the one below is the exact size or not but it made by the same people. I bought the longest one I could get to fit in the bed. I bolted it through the bottom to the existing frame with 4 bolts but I cut some 4" x 8" pieces of 1/4" flat aluminum to use as "washers" and disperse the stress. Since I needed to install a bar behind the seats to attach my seat belt harness to I welded a couple of plates to the bottom side of the bar which let me bolt down the back of the box also. I wanted a cooler so I used a 1/8" piece of flat aluminum to make a divider to separate about 1/3 of it. I made a 1" flange on both sides and the bottom and notched the top for the offset at the top lip. After test fitting I put RTV on the flanges, installed and rivited inside the box. Then I sprayed the cooler section with that flexable spray sealer (like they spray the sceen door with and put it in the bottom of a boat). After it set up I lined the cooler with 1" foam insulation. Oh yeah, I cut a hole in the bottom corner and installed a "boat plug" so I could drain it. It works perfectly with NO leaks! Plus, I have pleanty of dry storage and the box is water proof. Oh, bought two cans of that sealer. I used what I had left to spray the complete outside of the box. But first I removed all the stickers, cleaned with contact cleaner and scuffed with scotch bright. It has two really good latches on it and there isn't much way for water to get in it. I will try to make some picsof it this weekend.