there is not really a equivalent foot pound reading, just give em about 1/8th of a turn, what you are doing it putting the bolts into a elastic state, as for calibrating a torque wrench it depends on the brand of wrench on where you start looking for someone to tune it up, most of the time they are only with in 10 percent of dead on any way, sorta one of the reasons for the angle torque, the actual torque # is not super critical but getting a even torque across the head is more important
all america wants is cold beer warm cat and a place to take a poop with a door on it