I turn my 54 235 engine by turning the fan, but that's because the rad is out and easy to get to. Before I took it apart I made a short flat bar small enough to fit within the inside diameter of the crank pulley. Then I welded a nut to the center for a socket wrench. To catch the pulley I welded two bolts through the bar that stick out the opposite side of the bar than the nut, and fit into the two holes on the pulley. It doesn't take much pressure on the socket wrench to turn it over that way.

A day without laughter is a day wasted- Charlie Chaplin
When wrestling a grizzly bear, you have to keep at it until the bear gets tired, not when you get tired.
1948 Chevy 2-Ton