Edelbrock E-Series Cylinder Head Bolt Kit #85512 is a high-quality replacement set of bolts with washers for use with Chevy big-block engines equipped with Performer and Performer RPM aluminum heads. This E-Series bolt kit can be used on all Mark IV and Mark V engine blocks. E-Series bolts have a yield tensile strength of 190,000 PSI for strong and reliable loading with generous filleting throughout to eliminate stress risers. Bolt threads are rolled after heat-treating for superior form and strength, while a small hex head provides extra space for socket clearance in tight situations. E-Series Cylinder Head Bolts have a durable black oxide finish with sealer and come with the distinctive Edelbrock “E” stamped into the head.