rear shocks info wanted

I forgot to mention stacking more leafs can make a car ride very stiff or harsh.
You have some control over this with the rear segment of spring.
Shortening the leafs behind the axle will lighten the stiffness. Of course you don't want to shorten the main leaf. But you also don't want the ride stiffened up like a off road vehicle.
You want the front half of the spring very stiff. It is best if it acts as a solid traction bar.
The rear half only needs to hold the fenders off your tires during your usual style of driving so can be much softer.
So in the end you have a modified spring pack that has a very unflexable forward half
and a normal rate rear half but with extra arch built into it.
If you make sure all your spring mount pivot points are free and rotate easily when the bolts are tight your rear suspension will work properly. Pay attention to the rear shackle angle.
Depending on how much arch you added (shorter distance between spring eyes) may dictate moving the mount forward.
When you have the rear all set up at the new height recheck your caster on the front
wheels as you will have likely lost your positive setting and the car will be all over the
place and hard to control at higher speeds.