Edelbrock E-Series Cylinder Head Bolt Kit #85552 is a high-quality replacement bolt set for Chrysler small-block engines equipped with Performer RPM #60779, #60775, #60175 and #60179 aluminum heads. This E-Series bolt kit is required when installing Edelbrock heads on an engine previously equipped with iron heads. Included in this kit are two long bolts per head where the factory only has one. With Edelbrock and other aftermarket aluminum heads, use of washers are required and the bolts in this kit are longer to compensate for the included hardened washers. 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.