Limited Slip 373 9.75 Ford Differential. I put in 3 quarts M1 75W-140 LS friction modified gear oil with (1) 4 oz bottle of Ford's friction modifier. I probably wasted 8-10 ounces with pre lubing gears, axle bearings, axle shafts and splines before and during reassembly, with probably 2-6 ounces wasted from overflow, spillage, etc. while lubing parts. When filling, with the vehicle level, the fluid did not come out of the filler hole. My understanding was that this is the stopping point when the system is full. I cannot see how far below the filler hole the fluid is, and cannot tell by feel with my finger. My options: 1) Leave as is, knowing there may be a few ounces less than 3 quarts of fluid, plus the friction modifyer 2) Buy another bottle of Gear Oil and fill until it comes out of the filler hole as originally targeted 3) Add another 4 ounce bottle of Ford Friction Modifier (which I have), keeping in mind I have already added 1 bottle to the already fortified gear oil I have used. I want to do it right and price is not an issue. What would you do?