Vintage Finned Valve Cover Script SBC Center Bolt Machined Small Block Chevrolet ZZ6/Vortec Center Bolt Valve Cover Emissions Provision HolleyHolley is pleased to expand our Vintage Series line to now include a valve cover option for Small Block Chevys with center bolt heads. The Vintage Series family of die cast aluminum dress up products features a classically styled finned design and a retro style Holley script brandmark. These valve covers are standard height (3. 5 inch overall) with pre installed internal baffling, and come in a variety of colors and finishes for your unique