I read somewhere about using the old head bolts over again. (The Dodge Garage?) The idea is that the torque-to-yield bolts are O.K. to re-use them as long as they hold torque at 90 ft. lbs. If they stretch and do not hold the 90 lb. limit, they should be replaced. I have not used the ARP studs yet, but I believe that one should make sure that the final torque is around 85 to 90 lbs. after that final torque (1/4 TURN AFTER 65). The bolt stretch is what makes the fastening power. A similar problem can happen when tightening the rod bolts during an engine rebuild. Hot Rod magazine used a measure of bolt stretch and found that most of the rod bolts had not been stretched enough during the final torque. It is important to realize that the fastening power is not friction, but bolt stretch. That is why it is o.k. to lube the threads, or even use a thread chaser to reduce the friction.