First off the pre 91 motors had 9.0:1 compression to begin with, and the 91+ had 9.5:1. SO you must work off whichever you have.
.040" milled off for .7 to 1 point of compression sounds WAY off. On my 89 motor, I shaved .060", and from my calculations that much only took it to 9.7:1. The 91+...