Thanks goes to Lamplighter Productions for permission to post the following info from Dave Morgan's book;
Door Slammers: The Chassis Book

Dave's book covers race car suspension with great technical detail but presented in an easy to understand format.
This book is a "must read" for anyone modifying a automotive suspension system for performance or racing use.

I have used many of Dave's "tips" with success. For a Chrysler leaf spring rear suspension I found that building a leaf spring with a stiff and well clamped front sections is helpful. Set the arch of the individual leafs so when under load the overall spring assembly is near flat. On a drag car I add extra leafs to the front segment and make that section stiff and "dead flat". I also add a poly bushing to the front spring eye to help locate the axle and have the front section act more as a "swing arm". The rear segment should also be as flat as possible with only a slight positive arch, with the car sitting inactive and level . (the goal is to get the rear section level when the weight transfers back under light acceleration)
Body height is adjusted by moving the front and rear spring eye mounting positions up and down, combined with "lowering blocks" if needed. The rear shackles needs to angle rearward as shown above. A pinion snubber or "slapper bars can be used if additional axle "wrap-up" needs to be controlled. There are many other "geometery issues" at work so grab a copy of Dave's book for all the details.