Here is an article that shares some data points as well.
Yes; one can make minor adjustments by adjusting spring seat heights however generally at the expense of altered physical heights at the wheel openings.
Takes care
Shadowman
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The proper procedure for determining and fixing these settings: First, find the existing values using four wheel scales, with one scale placed under each wheel. All tires must have exactly the same circumference (measure them!), and be inflated to exactly the same air pressure. Disconnect the antisway bar links. The vehicle ride-height must be level side-to-side. If it's more than ½-inch off, check for frame damage; otherwise, it's probably caused by dissimilar length or rate springs. Fix these problems before weighing the car with fluids and driver.
The only way to change the left-side and rear weight balance is to physically move weight or ballast in the car. To lighten the left side, add weight to the right side--as far to the right as possible. If the front's nose-heavy, shift weight to the rear. Left and rear weights are interrelated in the sense that altering one of these usually affects the other to a greater or lesser extent. Both should be adjusted before fine-tuning vehicle crossweight. Relocating stuff changes weight distribution, but it won't change the crossweight percentage!
You change crossweight by changing the ride-height at any corner. Once you have the rear weight and left weight percentages as close as possible to 50 percent (for a standard handling application), go to work on the crossweight percentage. Raising the ride-height at one corner increases the weight on that corner, as well as the diagonally opposite corner; the other two corners will lose weight. Lowering the ride-height at one corner causes that corner and the diagonally opposite corner to lose weight; the other two corners will gain weight.
Coilover springs that adjust with a spanner wrench make changing corner height easy. Traditionally reserved for all-out racecars, these days they're being seen more and more on street-driven vehicles as well.
For cars with traditional coil springs, you can change the ride height with spacers or by repositioning the spring within the pocket. Cutting the coils is a last resort because it alters the spring rate (usually you want the same rate on each side of the vehicle, except on some FWD applications where spring bias may be needed to overcome torque-steer).
Very few production-based vehicles have perfect--or even near-perfect--weight distribution characteristics, but if you pay attention to getting the weight at each wheel right, the end result is a much better performing vehicle, and any further wheel, tire, and suspension enhancements will yield even more effective results
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