Edelbrock pre-1970 AMC V8 engines E-Series Cylinder Head Bolt Kit"Edelbrock E Series Cylinder Head Bolt Kit #85312 is designed for use with Edelbrock Performer Cylinder Heads #60129 #60139 and Performer RPM Cylinder Heads #60109 #60119 used on pre 1970 AMC engines with 7 16 inch diameter head bolts. This kit contains all of the necessary parts to replace the factory head bolts. E Series bolts have a yield tensile strength of 190,000 PSI for strong and reliable loading. Bolt threads are rolled after heat treating