The way I visualize weight jacking is what happens when you have a table with one table leg a bit too long. The table has most of its weight on the two diagonal legs which include the longer leg. Weight jacking is like putting small shims under the table legs until it stops rocking and all the legs carry the same weight.
Peter Jacks example is good, but if you think about what it tells you, it also opens opportunities if you can't find a good place to put the weight where you want it on the right rear.
Jack a little weight on the right rear. Its weight goes up a bit and that takes weight off the right front and left rear.
It might be much easier to put a little more physical weight on the right front and left rear than the same amount of weight right where you want it at the right rear. You can also shift the body just a fraction of an inch to one side relative to the rear axle.
A quarter inch here, a small spacer in a spring perch or a turn of a screw, a couple small weights on the right front and left rear could all add up to equal weight side to side and front to back.
Simple tests are much faster than major fabrication changes.
Buy a couple bags of sand and make test weights with small sand bags and try different locations and relative weights until you find the right combination. Then fabricate a physical weight of the same size and mount it as close as possible to where you had the sand bag, or relocate heavy components like batteries an small amount in the right direction if you can.
You don't have to use one or the other. Small changes in both the chassis wedge and weight can be used together to get where you need to be.
