I've been following a thread on another forum called "Make it Handle" and have made some of my choices based the info/data contained in that thread because it is truck specific and from a respected source with knowledge on the subject far greater than mine.
At this point, I should point out and I think David Ram said it best when he posted:
"I am not saying this is the only way, I am not even saying this is the right way, I am saying this is my way, lol!"
so in that regard I went down a slightly different path when choosing a rear sway bar - In fact, I took a sort of educated gamble that I could make something work not necessarily designed for a RAM 1500. Instead of going with the standard "off the shelf" Hellwig 7/8" or Addco 1" rear swaybar, I chose a Hellwig 1 1/4" rear bar in hopes that it better compliments the Hellwig 1 1/2" front bar. Of course the challenge will be getting it to fit and work correctly and that may ultimately prove to be a huge mistake but my intent is to let you know how it all works out whether I fail miserably or hit a home run or something in between.
So why go through the trouble to make a part fit/work that's not designed for the application I'm using it for?
Well, mainly because I think the intended application of the 1 1/4" bar while different is not so different it won't be terribly difficult to get it to work correctly; but we will see
But also because of this info:
"Lets get back to the main topic, HANDLING. One of the best upgrades you can do is swaybars. Swaybars, or Anti-roll bars, work by adding traction (downforce) to the outside tire. To do this, the swaybar has to take downforce away from the inside tire. So if you think about it, you can go 'too big' on the bars. If you went so stiff that the inside tire lifts off the ground, then that tire isn't helping at all. The balance between the front and rear bars is called "roll couple", and here's where a truck layout changes normal thought. In a normal performance car, with say 52% front weight and a low CG, the roll couple needs to be up around 80% (calc for this is really complex, so think of this as a comparison number), but in a truck, with 58% front weight and a higher CG, you aqctually need to move the roll couple BACK, maybe to 65%. This means that in comparison to a Camaro that would run a 1 1/4" front and a 7/8" rear, the truck would tend to 'need' a more evenly matched bar set. Say 1 1/4" front and 1 1/8" rear. Most retailers/manufacturers are missing this and selling bar sets in 'car' sizing, so be carefull.
From the set-up you have now, you can use the following rules for tuning.
A larger FRONT bar will "tighten" the chassis, making the truck tend to push, or not want to turn into a corner, also the rear of the truck will seam a bit stickier. A smaller front bar will do the opposite.
A larger REAR bar will "loosen" the chassis, the truck will turn into a corner easier, but the rear may want to slide around."
"Caster is a tricky thing. More + caster will give you added steering feel, or driver input, but, it will make it harder to turn. With modern power steering, the additional effort needed to steer is not reall noticed. The overall goal is to keep the tire contact patch as large as possible. Remember that as you turn, all sorts of forces are acting on the tires, pushing and pulling them around. As the sidewalls and tread flex, the patch gets smaller, and you loose traction. Setting up in anticipation of that flex is what were trying to do. I would be willing to give up some of the contact patch/traction when going straight, and max traction isn't needed, to gain some in a corner entry where it is needed. Stock trucks came with 1* or 1 1/2* + caster. The new Hotchkis kit will push that up to 9*+. For a "street driven" truck, I think 5* or 6* is the right range. Roll center hieght is a toughr goal to hit. Lets think about what is "reasonable" to acheive. It would be awsome to set the RC at the same height as the spindle pin centerline, but thats not going to happen. As a general rule, "higher is better", for RC. Try to keep it above 1/2 of the spindle height. So, if the tire diameter is 27", spindle height will be around 13", try to keep your RC above 6 1/2". This means drop spindles in favor of springs. Try to keep the swaybars close in size. 1 1/4" front with 1 1/8" rear is good for more streetable trucks, 1 1/2" front with 1 1/4" rear for more aggressive handling. - Remember that increasing caster will raise the pivit point ot the outer Tie Rod End, and could create additional bumpsteer, which will ned to be adressed in your design calcs."