This falls under the "just don't do it" rule of auto mechanics. Head bolts are cheap compared to what can happen if one fails. Just don't reuse them. Measuring torque on a fastener is an indirect method of measuring the amount of tension applied to the fastener. It's an approximation, since there are a number of factors that influence the torque reading on a wrench. The condition of the threads, the condition of the surfaces of the bolt head and nut, any lubricants on the threads, thread locker or anti-sieze all have an effect on torque readings. Measuring angle torque removes a lot of these other influences. The angle the fastener is rotated is a direct measure of the stretch in a bolt because the thread pitch is known. In racing applications where both ends of the fastener are accessible, mechanics actually measure the length of the fastener before torquing and after to ensure the correct amount of stretch is achieved. -- Mike > When reattaching the head, the manual recommends that once they're torqued > to the proper setting, you should angle torque 113 degrees. I've been > researching angle torque and have a pretty good understanding of it now but > what I'm wondering is if anyone has actually applied this method? >