Here's a tip I learned last night. When the Nova head bolts are too tight, it's a real pain to try to get them off without stripping the slot.

I used a Hudy off road wheel wrench that sat on top (not locked into) the handle of my flat blade screw driver and acted like a servo saver. It allowed me to add sufficient downward force and enough lock to twist, if it was too tight, the Hudy tool popped off. Simply it allowed me a good handle on the downward pressure and reduced the turning force requied because of leverage.