I was looking for the same information a little while back and only came across a measurement from the top. I'm looking and can't Find it right now but I know I saved it somewhere. I would love to know as well. Thanks
usually set the height of the oil with spring out and forks compressed. 90mm airgap should get you close. you need to buy atleast one quart of which ever weight you want. I want to say it will take around 10 ounces and then start measuring the airgap.