How an engine block?

1/2 inch ingersol rand impact wrench.

 

Stick it in gear

 

Agreed - use 5th gear, then (since the wheels will be off to get access to the front of the engine) have another person sit in the drivers seat and press the brake pedal while loosening the bolt.

The force of the brakes, combined with the mechanical advantage of the high gear, will provide more than enough resistance to prevent the engine from turning while trying to loosen the bolt.

 

You don't need to block the engine when using an impact gun. The short duration and rapid repetition of the impacts will not rotate the mass of the crankshaft, rods and pistons. The same reason an impact wrench doesn't try to twist your arm off when you use it.

 

Rather than an impact gun, is it possible to get a long breaker bar on the socket to get leverage (again using the brakes and transmission in gear to hold the engine).

Alternative proposal - I don't know if this is common in the Ferrari world, but in the Mazda Miata world it works great - let the engine starter do the work.

Determine the direction of engine rotation, it is clockwise when looking at the front of the engine through the wheel well. That means that if you put a socket wrench with the socket on the crankshaft bolt, brace the handle of the socket wrench against the chassis member or suspension arm rearward of the crankshaft pulley, so that the wrench against the suspension arm resists the rotation of the wrench along with the crankshaft - by using the starter to turn over the engine, the stationary socket wrench will back out the crankshaft bolt. You don't want the engine to start, just to rotate even one quarter of a turn to loosen the bolt. As long as your timing belts are in place, there's no harm in turning the engine over by one revolution even with cooling system etc. drained.