What you are mainly doing when you shim them is you are pulling the spider gears back into the original tooth contact. Just because you take off .030 from the face, it doesn't mean the cone is going to sit .030 deeper into the cup. The angle dictates how far down the cone sits. And many think you're shimming them for more grip. That's somewhat true but it's much more for tooth contact between the spiders and the side gears. I'll tell ya, when the thing tries to spin one and not the other wheel, you're getting lots of force exerted on it for grip. One of the biggest killers of limited slip rears is having one wheel on good hard surface and the other off the shoulder and on dirt. I also try not to be on the gas hard when making a turn at a traffic light. One more thing....7mm is nearly .300" isnt' it? 1mm is .039" If you've already taken that much off, oh well. It'll work still. Wait...you said .7 never mind lol