Anyone got a good link/lead on fairly priced cargo boxes. Looking for silver or black that sit behind the cab (in bed). Will the above the rail affect my turning radius and future 5th wheel?

 

I got one of these in black originally for my 6.5 ft bed F-150, but I have kept it in my 8ft bed F-250. very useful and is not in the way of anything.

Specialty Series Narrow Tool Box

 

i have one as well on a 6.5ft bed. since most of the stuff in it was trailer support stuff...I moved it to the toung of my trailer.

the question of limited movement with a 5th wheel is def something to check into. 16 inch box on a 6.5 foot bed, doesnt leave much room around the 5th wheel.

 

What do you plan to keep in it? That will drive the cost more than anything else; if you just want to move some straps and a 4-way out of the cab any cheap box will work. If you want to keep tools or anything with any value you'll want a more expensive box with better locks.

My rough (non-exhaustive, entirely based on personal experience, and very subjective) list starts with RKI and Weatherguard followed by high end Deltas, mid-level major brands (Delta, Lund, Dee Zee), then whatever rebranded box-store box you can find (Tractor Supply, Husky, Kobalt, Craftsman,etc). If you have a Tractor Supply near you, mine carries Delta, Weatherguard, and their house brand, so you can compare a lot side by side easily.
http://www.tractorsupply.com/en/stor...el-truck-boxes

Steel vs aluminum is IMO mainly a weight issue, in that a steel box will run 1.5-2x heavier than an aluminum box. Steel will support a lot of weight better if you're really going to load it up. On cheaper boxes look for some kind of foam and gusset reinforcement on the lid or you can bend them in by standing on them, meaning that aren't that strong. I've used Weatherguard and RKI in steel, and Weatherguard in aluminum, and at that level I don't see a lot of differences at that level between the two materials, but on cheaper boxes you can really tell when they start using thin sheet metal.

If you have an 8 foot bed in addition to a normal saddle box you should consider a chest model that doesn't go over the rails, or a low-profile saddle box. If you have a 6.5" bed I'd stay with a chest model. My box is a solid 5 inches above the rails, I think that's getting close to being too high and close to a 5th wheel, especially on a short bed. Gooseneck no problem but those trailers typically have tapered noses.

You can also install a chest between the hitch and tailgate if you have enough room, that seems to be common if you put a transfer tank in front of the hitch.

 

I have a challenger low profile and I love it. It only comes about 2" above the rail if mounted directly to the rail (mine is ontop of a back rack. Here is a picture for you. A low profile is available in most brands.

 

I've got to agree that Tractor Supply is a great starting point. Our local one carries the same as listed above and they have them all out so you can compare side to side. I'd also agree that if you want top notch, Weatherguard is the way to go and they do now offer low profile units that would leave plenty of 5th wheel clearance. I have the standard height one, mounted on a backrack, and it's got to sit 7 inches over the bedrails. Blocks the lower 1/3rd of the rear window, so it's only in when I need the storage space.

I had a Dee Zee Competitor Series "mid level" box for 7 years prior to the Weatherguard, and it was a great box. Just I stumbled onto someone that bought a 27" Weatherguard and realized how much bed space it took in a short bed, and wanted to trade straight up for a smaller box............Jumped on that fast as I could!

Also, Senix posted pictures in a thread somewhere of the Ranchhand headache rack/ toolbox combo he has and that is also a very, very nice setup that is low enough profile for 5th use.