I use the EOIC on my stock slants, only because I'm used to doing it when I had a race car.
If it's a stock slant, Rapid R's method, and the one on the Allpar link will work.
I pull the plugs to make it easy to turn the motor. Use Rapid R's advice to turn it with the fan, most slants don't have a crank pulley bolt like small and big blocks, so turning it with a socket wrench is out. If you want to add a crank bolt, hit the JY and look for a slant in a truck, many had the bolt.