ooo found a good info stolen from
http://www.off-road.com/tlc/faq/modify.html
Ride Harshness
Rob Mullen
Short wheel base trucks ride rough and there is not a whole lot that can be done about it. There are a few options to soften the ride though. In order of "Bang-For-The-Buck" they are:
AVOID ADD-A-LEAFS!
These will make your Cruiser ride like the axles are bolted directly to the frame.
Keep lifts as small as possible
The higher up you are, the more pitching motions of the truck are amplified.
Use the right shocks.
In BC, the preferred shock set up for FJ40's is 70/30 Gas charged shocks (like KYB Gas-A-Just) up front and 50/50 Oil shocks in the rear (Like Rancho RS5000) The B series engines are lighter than the F's so 70/30 shocks in the front give a _VERY_ harsh ride. The preferred set-up for BJ-40's is 50/50 oil shocks at all four corners. This may also be the best set-up for V8 Owners
If you have the Rancho 2.5" 7 leaf Lift, you can improve the ride quality by modifying the spring wrappers. Rancho makes the wrappers too tight for proper spring movement. If you pry open the outermost sets of wrappers, the ride will become softer and your articulation will increase by several inches. The remaining three wrappers are sufficient to prevent spring pack shifting.
If your truck is lifted, you can soften the ride by removing one of the short leaves. Unfortunately, removing a leaf will also decrease ride height.
Front shackle reversal
Reversing the front shackles allows the axle to pivot up and backwards (away) from obstacles instead of forwards into them. Shackle reversal will also decrease bump steer by keeping the steering linkage geometry constant over obstacles. Reversals that recess the shackle mount into the frame are superior because they do not increase lift, and the fixed front mounts are not as likely to become "boulder finders" However, they may also create shackle movement problems.
Polyurethane Bushings/Greasable Shackles
Adding polyurethane bushings will not soften the ride but will improve handling by preventing the springs from twisting relative to the mounts. Polyurethane is also required for greasable shackles because dino-based grease will break down rubber bushings quickly. Using after-market shackles will further improve handling by resisting shackle twisting, while greasable pins allow the springs to move more freely to absorb bumps.
then look at it. That's just how I do things 
