Sorry, I measured the other night and then totally forgot to post.
The top perch is stock height in the rear and a little bit lower in the front, maybe 1/8" lower in the front.
So the perches will adjust the height of the car a decent bit. The front much more than the rear. If you drop the perch in the front 1" the car will lower a lot more in the front than if you were to lower the perch in the rear 1". It would be nice if that took that into consideration and set the perches based on the geometry. But they didn't, so if you're messing with it, you might have to play around a little to get it to look right. For example, the lowest perch in the rear might work best with the middle perch in the front. Depends on weight distribution and spring rate and all of that as always.
Tim