Head bolts perform one of the toughest jobs on a vehicle. On a stock engine operating near wide-open throttle, each bolt may have to withstand more than 5 tons of combustion pressure.
Federal-Mogul's Fel-Pro® brand offers a line of OE-quality head bolt sets, including torque-to-yield designs.

In addition, Fel-Pro offers a torque-to-angle indicator (part number TRQ-1) that takes the guesswork out of tightening head bolts. It’s an inexpensive gauge that fits on the 1/2” drive of a torque wrench and ensures torque-to-yield bolts are properly tightened.

Fel-Pro engineers recommend you never reuse a torque-to-yield head bolt. Chances are great that it has already exceeded its elasticity barrier and won’t spring back to properly seal the engine.