What the hell is lever suspension? I don't know but i'll give anything a try.
I guess it is well known as Bagi suspension but I really don't know much about the theory, for me it's all practical testing. It took me a while to get this kind of setup working smoothly and with least resistance and there are a lot of variations on the interwebooks.
Newer variations of this setup have the rocker arm on the shock tower and a more complex lower mount.
Not wanting to move my body mounts, this was a good solution.
Pay special attention to binding of the ball ends and make sure there is no binding for least resistance.
Simply getting everything to fit right was a real challenge. You want to have a decent selection of spacers, screws and ball ends before you start a project like this.
My first attempts were not so great. And my first test run was still a bit too stiff.
Don't worry about the shape of the lever too much. But it should be unequal length. the longer end compressing the shock.
1. Compression adjustment.
This length of the lever makes the difference to compression rate, so using spacers to make it longer or shorter are a tuning point. Mine is 5mm longer on the shock side.
2. Ride height
Ride height is adjusted by the turnbuckle length. Preload of spring should be ignored in theory. But in reality I tune my car a lot using preload settings.
I didn't really notice any major advantage or disadvantage as yet.
So I'm having a second crack at it as I've got it a bit softer and working more smoothly.
See how the second test goes.