Where to drill precisely drill holes for clutch pedal and clutch master cylinder
 

I'm in the midst of performing an auto to 6 speed conversion for my 06 G35. How do you figure the exact spots to drill for the and clutch master cylinder? Because there is no stamped imprint on the firewall to give you an idea of where to drill holes like the 240SX chassis has. Was wondering if creating a template from a car that already has the holes drilled for the and clutch pedal would work or is there a better method of figuring out precisely where to drill holes? I want to avoid drilling holes in the wrong places and have the line up against the break pedal at the wrong angle, or have the clutch pedal sit too low, too high or too far to the left or right of the break pedal.