Flywheel alignment question

[wrndln]

I made a flywheel housing alignment tool and measured the alignment a number of times not getting very good measurements - especially at the 3 o'clock position. I finally did the following: I have two .010 horseshoe shims installed on each of the top two bolts, no gasket between the engine & housing, and the bolts torqued to about 50#. Here are the readings I get at four places. 12 o'clock .009, 3 o'clock .017, 6 o'clock .012 and 9 o'clock .008. This is as close as I have gotten. I don't know why I need two shim with no gasket installed and why the 3 o'clock measurement is quite a bit larger than the other measurements. I have attached a picture of my setup below. I am wondering if I should add a .010 shim somehow to the 3 o'clock position to get the measurements closer. Does anyone have a suggestions about what to do to make the alignment better?
Rusty Nelson