My friend bought a maxima and whoever gad the car before him left about 3 off.
Any help ?

 

I don't know the bolt size. It might be in the FSM. Go to a wrecking yard and collect lots of bolts for cheap.

 

Eh.....take one off and use it as a go by when you go to Home Depot or Lowes.

Remember those bolts are torque'd very lightly, and in inch-pounds! Torque spec and sequence in FSM.

 

Go to a junkyard, and remove the easier front valve cover bolts for what you need. I always like to use exact bolts especially since you have to tighten in sequence in the valve cover bolts. Autozone has a diagram for the correct sequence. The "front" of the engine is actually facing sideways where the belts are. It's not facing the radiator.