What Spike said is correct.It all depends on the uses of YOUR truck.And what you want out of it.I know if you lower the back 2 inches and relocate the battery to under the truck your ft to rear is changed almost 2% to the rear.Pinion angle is a big factor if you have a huge angle you are using hp to turn the shaft as well as a vibration.As for brake bias you can run a more aggressive pad on the rear[to get more brake] and a stock or medium pad on the ft.By doing that you will help in resisting fade and have a more neutral braking vehicle.There is alot more than that too,ie. brake dive,scwat[sp],steering angles and turning angles plus the angles of your sway bars affect how your truck can and will handle.Stan
I other words buy a kit that keeps all that in prespective.Don't try and do it the cheapest way do it the right way!