Edelbrock E-Series Cylinder Head Bolt Kit #85582 is a high-quality replacement bolt set for big-block Oldsmobile engines equipped with Edelbrock Performer RPM cylinder heads. This bolt kit is required when installing Edelbrock heads on an engine previously equipped with cast iron heads. With Edelbrock and other aftermarket aluminum heads, a washer is required which this kit provides along with longer bolts to compensate for the added thickness of the included hardened washers. E-Series bolts have a yield tensile strength of 190,000 PSI for strong and reliable loading. 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.