Chevy BBC 454 Chromoly Head Bolt Kit These Speedmaster aluminum pulleys are

These Speedmaster aluminum pulleys are made from a 356 aluminum alloy that is heat-treated to T-6 specs

These Speedmaster aluminum water pump pulleys are made from a 356 aluminum alloy that is heat-treated to T-6 specs

They are designed to ensure belt retention at high rpm

1966-83 trucks and Suburbans

chrome plated for a shiny finish

Chevy BBC 454 Chromoly Head Bolt Kit These Speedmaster aluminum pulleys areSpeedmaster cylinder head fasteners are made from aircraft quality 8740 high tensile strength chromoly steel and cold forged to ensure molecular integrity. They are heat treated prior to thread rolling and machining and are rated at a whopping 190,000 psi. All kits come complete hardened parallel washers for an even load distribution and accurate torque readings.