At the end of the day I always run all the fuel out of it but there is no way to do that after a race. I usually bump the flywheel with my thumb. If you think about it, consider the forces being put on the rod when the engine is running at over 30,000 rpm. Then consider the forces at say, 2,000 rpm. Not even a comparision. Going by my amatuer physics classes the sudden stop from 2000 is still much less than normal running at 30,000. This is my preferred way to stop my engine, a small block of course.

The other "best" way to stop an engine in my book is by plugging the exhaust. This does not put any extra strain on any components and does not starve your engine of oil. It also helps for restarts because the engine has been preprimed. A quick bump on the box or tug at a pull start will bring it to life every time if you shut it down this way.