Harland Sharp original series, "Adjustable" pedestal mount, GM LS1/LS6 roller rockers are not designed to be a replacement for the factory rocker system.
These adjustable rockers are designed to mount to the factory location. They do require shorter pushrods and additional clearancing to the cylinder head. We recommend them only to be used for serious racing applications.
Default Harland Sharp Shaft Mount Adjustable Roller Rocker 1.7 Ratio Variant