Went through all this about 4 years ago. Bought new rear springs from VB, installed them - and the rear end sat way too high (although I did not measure and have no numbers to report).
I finally moved the lower leaf to the top of the leaf sandwich on both sides (notice, I did NOT remove the leaf - I just put it back in on top so as to keep the original sandwich thickness). I just reasoned that that should take out some arc. It worked fine and gave me the height I was looking for (distance from center of axle to bottom of chrome strip is 15" in the rear and 13 1/2" in the front). If the rear springs ever sag (which I expect they will, eventually), I'll just move everything back to its original position.