I apologize for what I said.
There are certain rules you don't do, if I remember correctly, and shimming something where shear loads are/can be involved; you have to have the right components and what/where they are attached to is machined correctly. The PP and the flywheel are in potential sudden shear when the clutch disc is engaged (suddenly clamped tight between the two of them).
Back in the mid to late 60s or early 70s I was at the dragstrip when one of the guys I knew had the clutch blow in his "55" Chev gasser and it broke the bell housing apart so the trans fell out of the car and slid along down the track just in front of us; we were at the finish line when it happened. Mandatory "Scatter Shields" came along at about the same time. He also had his starter suddenly engage in about the same time period... again, at the finish line.
Lee