See the pic in post #52.

Some Sockets have too large of a tapered radius and they don't grip much of the bolt head. Grinding most of the tapered radius off allows the socket a better bite on the bolt.

If the bolt is a 6 sided hex sometimes a 6 point socket is better. Note that I have never scene my flex plate.

__________________
84 300D, 82 Volvo 244Gl Diesel