Kevin, The bolt holes are around the edge of the flywheel. It is flat except for the small groove near the edge. I noted some gouges in the flywheel that were not on the clutch plate just an uneven wear pattern. I suspect the shop that built my engine did not resurface the flywheel they used. They did not use the one I sent them from my old engine. I attached some pics below. Oh the impact wrench was the way to go. Not sure why I did not use it from the start, I was using my impact sockets with the breaker bars because they are 6 point and grip better.