New to the board, but the information is priceless.  Long story short I picked up a very, low milage (5,700 to be exact) 272 ECG block stamp and I am going through it to clean it up and change gaskets ect. 

It came out of a large truck and has the large engine mount on the front and does not utilize the traditional side mounts.  I am using the side mounts and want to remove the front mount.  The only way to do this is to pull the harmonic balancer because there is no clearance with the forms of the mount.  The motor is on the engine stand and when I put the breaker bar on it the whole engine just turns and I am not sure what the best way to keep it from turning is?  I just don't want to damage the engine.  Any tricks/suggestions?

Thanks in advance guys!

~Ryan