In the pic are stock bolts and arp, was told 45 years ago at my first car repair job to never use any bolt that did not have the cutout head on a flywheel. Now I know exactly why. Notice the arp has even more contact area on the flywheel than stock bolt no cuts in head and they are undercut. I do all mockups to check and correct flywheel runout with 7/16 head bolt washers, even with a new flywheel the place bolts distort the [censored] of of the washers, worse on a used wheel. That is why I never use washers. Thanks for the info