The magical mysteries of WP shackles...
skender,
Go with the WP shackles. They are inexpensive, heavy duty, simple to install, and will give you exactly what you are looking for- increased height and no change in ride quality.
There has been an ongoing frenzy regarding the application and resultant effects of adding the WP extended shackles. One guy noted that they even increased his acceleration. (Hmm, must have been the gold plated ones.) I must admit, when I installed my WP shackles, I was somewhat overcome by a newfound admiration as I stood back and gazed upon my "studly rig". I couldn't wait to take 'er for a ride. I would imagine it to be like buying a boob job for the little lady. "I couldn't wait to..."
And all this for 50 bucks and a half hour's work. I was impressed. It was kinda "tingly".
Putting the sentiments aside, WP shackles are no more than extended mounts for your leaf springs. They do not affect the spring rate. They do not change the load carried by the springs. They do not instantly flatten your leaf springs. How could they??? The arc of the leaf spring is determined by its resistance to the load it carries. None of this is changed by extending the mounts by three inches(adding WP shackles).
I will point out that the increased distance between the axle and the bump stops does allow for more upward travel of the suspension at full compression. This could cause some flattening of the leaf springs over time because they can be "pushed" farther at full compression. Fear not... This is not a bad thing and unless your out "twistin' it up", stuffing your suspension to the max, you shouldn't be affected by this "gravity surge".
If you find the WP shackle installation too easy, and you're feeling a bit guilty about getting too much for too little, go ahead and decide to replace the leaf spring bushings with some fancy urethane ones while your at it. After about four hours of beating and cutting and grinding, you get to do the other side. This procedure should somewhat offset that "tingly" feeling...
[Edited by wabbit on 02-11-2001 at 09:17 AM]