The only drawback with the fuel tanks from a weight/traction standpoint is the weight is not over the wheels or towards the rear of the bed, so you lose some leverage there. But yes, I definitely have a much better ride with only 50 gallons in my 1st Gen bed tank (while it's full, that is) and the benefit of only needing to fuel up every 2 months far outweights that for me, no pun intended!

I use sandbags in the back of the '07, and installed a reinforced cross-bar that bolts down between them and the wheel humps to keep them in place under "non-optimal" stopping conditions.

 

To add a thousand pounds to you bed, just dump a bunch of Reese's peanut butter cups in it, then I'll give my ex wife your address.

You guys keep mentioning bolting stuff in over the axles; I keep visualising using my old style fifth wheel hitch for this very application; just strap whatever weight you're gonna use to the crossbar. (or, alternately, dump a bunch of Reese's in the bed......)

 

I ended up using 8 concrete pavers. Picked them up for free; they are 90# each. Getting rid of them this week.

 

Water softener salt works pretty good. 15-20 bags at 40lbs each. $5 a bag and I use them anyhow in the water softener and salting the driveway.

 

It's wonderful if ya wanna salt the hell outta your bed, anyway. I'm trying to think of something like a tractor weight that would mount to the tailgate or the very back edge of the bed; maybe something like a sand weight. If you get it as far back as possible, it'll squat your truck a little more than if it's right over the axle. You don't however, want so much weight that it'll ruin your handling; if it causes you to lose traction in a turning manuvuer, you have WAY too much weight!

 

The bags are thick plastic, besides a few lbs of salt dumped in the bed isn't anything compared to how much is used on the roads and gets kicked up on the truck.