antman89iroc

I have a Diakin aftermarket replacement for GM's lightweight flywheel. I noticed something strange when I took it to the machine shop for resurfacing. On the engine side there are drilled areas where it was balanced from the factory. On the clutch side there is noticable color differances in the friction area which correspond with the drilled holes in the back. Sort of a shadow in the bluish area where the clutch was slipping. I thought it may be from the differance in thichness expanding with heat. It's like the thin area isn't as blue as the rest. My concern is that if this flywheel is so thin in areas, could that have played a part in my clutch slipping if the flywheel was flexing? Has anyone out there had a simular situation with a lightweight Diakin steel flywheel?