Torque Spec for the Harmonic Balancer Pulley Bolts??

Here ya go.... note that plated bolts (Zinc or cad plated) get less torque, as the plating makes them slicker, and thus they will reach a higher level of stress/strain in both threads and bolt if you run them to the same torque as non-plated ones. (And oiled threads acts like plated threads...)

Tightening Torque Guide

Edit to add: BTW, the grade of the bolt is just one half of the situation... the thread stress and strain of the nut or whatever you are threading the bolt into has to be considered. If the nut (or other internal threaded objust, like your damper) is of a lower grade, then the limits on the lower grade material determines the limit. I would suspect that the damper material is more like grade 5 than grade 8.....so I would stick with the grade 5 limits. (And would also use some blue Loctite if I wanted peace of mind.)