Bill, you're coming at this from the right end, so here's a bit more information...
Ride height is ride height and you've got that sorted. There is a slight 'curved ball' with the front end - your static ride height is also your static castor. You need to get both as close as you can to where you need to be.
Start with the static castor. With the car on the ground, fully laden, use a camber gauge to measure the static castor - the angle of the kingpin to the ground. I usually start at four degrees.
Wind the downstop grub screws well away from the chassis. Adjust the nut on top if the spring until you get four degrees castor. Adjust both nuts the same and together otherwise it all goes pear-shaped! Now wind the downstop grub screws all the way in until they just touch the chassis.
As a rule of thumb more castor means less turn-in but the car will exit the corner well, and less castor gives more turn in but less steering coming out. Find a balance you like and adjust it to the track features as you see fit.
Next, change the washers above and below the steering block until you have your ride height right. We're done here for now.
At the rear wind the centre downstop screw well away from the chassis. Adjust the springs until you have about 2mm of 'sag' or 'droop' (I call it droop) in the chassis. Car fully laden, adjust the springs until the chassis sits with 2mm of movement when you pull it up to the stops. Now screw the downstop down until it just touches the chassis.
Using the eccentric inserts, get the ride height you need.
Now you should have a car at the right ride height on which the suspension at both ends does not drop down when you lift it off the table/pit board. It should have the ride height you want at both ends. Get it like that before we get to the next bit.
You can now set the droop at both ends by unwinding the downstops. As a rule of thumb start with 1mm at both ends. Unwind the screws evenly on both sides, lift the car up until the downstops touch the chassis and slide in your ride-height gauge. 1mm droop means that what reads 4mm on your ride-being gauge ready to race goes up to 5mm when you lift the car up until the downstops touch the chassis with the wheels still on the ground.
Now you can tune the handling. Rear droop will give you weight transfer to the front - the more droop the more weight transfer but the longer it takes the car to settle as you come off the throttle to turn in. I run 1mm, David Gale runs 0mm as he likes the fast reaction he gets when turning. We both increase this if the track is bumpy as it smooths out the ride.
Front droop is usually left alone - 1mm seems to work for everyone.
The rear downstop is not a pivot. If it touches the chassis during roll you have something else wrong! As the car rolls it will sink into the suspension so the downstop won't touch. It will touch a lot in bump as the car moves up and down over bumps. Try adjusting rear droop and see what you like to have for your driving style.
I hope that helps, but where my explanation is obscure shout up and I'll have another go! HTH
