Seems like a lot of math to learn a capacity that can be simply found empirically. Eight quarts (US quarts) fills my '72 107 to the top line when I change the oil and filter. The small amount in the oil cooler is insignificant, but if you do drain it (that extra little copper gasket in your filter kit is for the cooler drain plug) you'll still only need 8 quarts. These cars have a whoppin' big oil capacity so being off a few ounces is not material. You'll see more difference when you check the level at various times after shutting off the engine. If you are between the lines on the dipstick, and not over-filled, you'll be fine. Don't sweat the small stuff. Whole other story when measuring ATF...that needs to be precise.

That said, I was deeply concerned about capacity the first time I changed oil in my 107 and for the same reasons...bought 9 quarts because it seemed right and only used 8. Next time I only had to buy 7 quarts.

Put in 8, it'll be great...(hey, that rhymes!)

230/8